WASHINGTON -- Randy Johnson had to wait a while for his shot at 300 wins. The crowd was small, and the weather was wet. His performance, however, was more than worthy of the occasion.

The Big Unit hit the big number on Thursday, becoming the 24th pitcher to reach one of baseball's most revered milestones. Johnson tossed two-hit ball over six innings, leading the San Francisco Giants to a 5-1 victory over the Washington Nationals in the first game of a doubleheader.

Johnson allowed only an unearned run and threw 50 of his 78 pitches for strikes. He faced four batters above the minimum and got spotless relief from his bullpen.

He left leading 2-1, but nearly wound up with a no-decision. The Nationals loaded the bases with two outs in the eighth before Adam Dunn was called out on strikes with a full count on a knee-high fastball from reliever Brian Wilson.

San Francisco added three runs in the ninth.

Some of the few thousand fans who witnessed Johnson's victory -- the Nationals have trouble drawing a crowd for anything these days -- chanted "Randy! Randy!" in the bottom of the ninth. When the game was over, he gave hugs to teenage son Tanner, who served as a Giants batboy, as well as his teammates. Johnson then tipped his hat to the cheering crowd before disappearing into the dugout.

Johnson (5-4) became the sixth left-hander to win 300 games, and the first pitcher to do it on his first try since Tom Seaver in 1985.

The 45-year-old Johnson is the second-oldest pitcher to reach the milestone. Knuckleballer Phil Niekro was 46 when he won his 300th with the New York Yankees in 1985.

As long as it took to get to 300, the final step for Johnson required quite a bit of patience. Two off days in the Giants' schedule and a rainout Wednesday night gave him seven days of rest since winning No. 299 last week against Atlanta. In addition, Thursday's game was delayed 36 minutes by bad weather and was played in a light rain.

Johnson had an efficient outing, not flashy. He didn't allow a baserunner until a walk in the fourth inning and didn't give up a hit until Elijah Dukes' broken-bat single up the middle in the fifth.

After Dukes' hit, Johnson walked Austin Kearns to give the Nationals runners on first and second with none out. But second baseman Emmanuel Burriss thwarted a rally with the defensive play of the game. On a one-hopper that hit the mound, Burriss dived to his right to stab the ball backhanded, then flipped it out of his glove to shortstop Edgar Renteria to start a dazzling double play.

Johnson himself hit the turf after a comebacker that he knocked down in the sixth inning, barehanding the ball while falling forward to throw out pinch-hitter Anderson Hernandez. The Nationals scored their only run off Johnson later in the inning, after Renteria's throwing error allowed Alberto Gonzalez to reach first. Gonzalez was doubled home by Nick Johnson.

Johnson got the run support he needed early, when Juan Uribe's RBI grounder and Burriss' RBI single off Jordan Zimmermann (2-3) gave the Giants a 2-0 lead in the second.

After Johnson left the game, relievers Brandon Medders, Jeremy Affeldt and Wilson took care of the rest, although Wilson's strikeout of Dunn was a borderline call disputed by the Nationals slugger. Wilson also worked the ninth for his 13th save.

The fans at Nationals Park could be the last to see someone reach 300 wins for a long time. Pitchers are handled with more caution than ever, making it more difficult for even the best to post big-win seasons with regularity. The four active contenders with more than 200 wins are advanced in their careers, and promising younger candidates such as Roy Halladay (140 wins) probably won't get close for at least a decade.

Several hundred were in the ballpark when the national anthem was sung at 5:03 p.m., with the biggest cluster surrounding the Giants bullpen in left field, where Johnson had been warming up.

Johnson joined Steve Carlton as the only pitchers to win No. 300 against the organization with whom they made their major league debut. Carlton started with St. Louis on April 12, 1965, then beat the Cardinals on Sept. 23, 1983, at age 38 while with the Phillies.

Johnson's first three wins -- exactly 1 percent of his total -- came with the Montreal Expos, long before the franchise moved to Washington. His first victory was Sept. 15, 1988, five days after his 25th birthday, but most people noticed him only because, at 6-foot-10, he was the tallest player in the majors.

San Francisco completed a sweep in the nightcap with a rain-shortened 4-1 victory. The game was called with two outs in the top of the sixth after a 67-minute delay.

Matt Cain (7-1) won his fifth straight decision, beating Ross Detwiler (0-2).

• Pirates 11, Mets 6: At Pittsburgh, Jason Jaramillo drove in four runs, prized prospect Andrew McCutchen had a productive major league debut and Pittsburgh completed a rain-shortened, three-game sweep of New York.

Ramon Vazquez went 4 for 4 and Andy LaRoche had two RBIs for the Pirates, who played their first game since trading All-Star center fielder Nate McLouth to Atlanta on Wednesday.

The deal made room for McCutchen, a 22-year-old speedy center fielder. He went 2 for 4 with three runs, a walk, an RBI and a stolen base as Pittsburgh roughed up Mike Pelfrey (4-2).

Carlos Beltran, playing his first game in five days because of a stomach virus, homered and doubled off the wall for the Mets, who have lost four of five. They were swept on the road for the third time this season.

The depleted Mets also got a double dose of bad news: injured shortstop Jose Reyes (calf) now has a tear in his right hamstring and reliever J.J. Putz is experiencing elbow pain.

Steven Jackson (1-0) got his first major league win in his second game with two scoreless innings of relief.

• Marlins 4, Brewers 3: At Miami, Josh Johnson hit a three-run shot for his first career homer and pitched into the eighth inning, leading Florida over Milwaukee.

John Baker had an RBI single in a four-run fourth for the Marlins, who took three of four from the NL Central leaders. Matt Lindstrom worked a scoreless ninth for his 11th save.

Johnson (5-1) allowed two runs and five hits in 7 2-3 innings. He walked one and struck out eight in earning his first home victory since April 12.

He connected off Dave Bush (3-2) in the fourth to give Florida a 4-1 lead.

Prince Fielder hit a two-run homer and an RBI triple for the Brewers.

• Cardinals 3, Reds 1: At St. Louis, Chris Carpenter pitched a three-hitter for his first complete game in more than two years and Albert Pujols took care of the offense with a two-run homer and RBI double, leading the Cardinals to a win over the Reds.

Carpenter (4-0) needed just 95 pitches for his first complete game since Sept. 11, 2006, at Houston and 26th of his career. With the help of two double plays, he faced the minimum through 7 2-3 innings. Carpenter's ERA rose to 0.71 ERA.

Laynce Nix spoiled the shutout bid with his 18th homer to right field in the eighth.

Aaron Harang (5-6) went the distance in losing his second straight. He gave up eight hits, striking out three and walking two in eight innings.

• Rockies 10, Astros 3: At Houston, Garrett Atkins broke out of a slump with two home runs and Colorado snapped a four-game losing skid.

Ryan Spilborghs and Brad Hawpe added solo homers and Jason Hammel pitched seven effective innings for the Rockies, who avoided a sweep and stopped Houston's four-game winning streak.

Hammel (2-3) allowed two runs on four hits with four strikeouts in his longest outing of the season.

The Rockies pounded Wandy Rodriguez (5-5), who lost his third straight start after winning his previous four decisions. Rodriguez came in with an 0.79 ERA at Minute Maid Park, but gave up seven runs and 10 hits in five innings.

• Phillies 3, Dodgers 0: At Los Angeles, Cole Hamels turned in another dominating performance against the Dodgers, pitching a five-hitter for his third career shutout, and Philadelphia extended its winning streak to seven games.

In his first start in Los Angeles since winning the clincher of the NL championship series, Hamels (4-2) threw 97 pitches, retiring 18 of his last 20 batters and allowing only two runners as far as second base -- one of them on defensive indifference in the ninth. The 25-year-old left-hander struck out five and walked none while lowering his ERA to 4.40.

Clayton Kershaw (3-4) threw 105 pitches over 5 1-3 innings, allowing two runs and four hits.

American League

• Yankees 8, Rangers 6: At New York, Melky Cabrera hit a tiebreaking, two-run homer in the eighth inning and the New York Yankees overcame yet another poor start by Chien-Ming Wang to beat the Texas Rangers.

The Yankees rallied from a 5-1 deficit and took two of three from the AL West leaders.

It was another game of home run derby at the new Yankee Stadium. Johnny Damon started it with a leadoff shot for New York, Nelson Cruz finished Wang in the fifth with a long drive and Ian Kinsler's solo homer for Texas in the sixth made it 6-all.

David Robertson (1-0) threw one pitch and got the win, retiring Elvis Andrus on a fly ball to end the eighth.

• Angels 6, Blue Jays 5: At Toronto, Howie Kendrick dashed home with some daring baserunning, scoring the go-ahead run on a ninth-inning double play to help the Angels beat the Blue Jays.

Justin Speier (2-1) got the win despite giving up a tying sacrifice fly in the eighth. Brian Fuentes closed it out for his 14th save in 17 chances, striking out Jose Bautista to strand runners at first and second.

Trailing 5-2 after seven innings, the Blue Jays tied it with a three-run eighth against the Angels' beleaguered bullpen, which came in with a major league-worst 5.68 ERA.

Brandon League (1-2) took the loss.

• Twins 11, Indians 3: At Minneapolis, Jason Kubel hit a pair of three-run homers to back Scott Baker, who pitched seven effective innings for the Twins in a victory over the Indians.

Kubel's first homer capped a four-run first inning against Fausto Carmona (2-6). The cleanup batter followed an inning later with his second to give Minnesota a 7-0 lead.

It was Kubel's fourth career two-homer game and second of the season. He also hit a pair April 25 at Cleveland.

Justin Morneau added his 15th home run of the year and drove in three runs for the Twins.

Baker (3-6) struck out a career-high 10 and walked just one. He allowed three runs -- two earned -- and six hits.

• Red Sox 6, Tigers 3: At Detroit, Jason Bay's bases-loaded double keyed a six-run third inning and the Red Sox completed a three-game sweep of the Tigers.

Tim Wakefield (7-3) got the win, giving up three runs and five hits in 6 2-3 innings. The 42-year-old knuckleballer has beaten the Tigers 16 times, more than any other active pitcher.

Three Boston relievers finished, with Jonathan Papelbon pitching the ninth for his 14th save in 15 attempts. The Tigers put two runners on base, but Dustin Pedroia's diving stop at second base helped Papelbon escape unscathed.

Dontrelle Willis (1-3) took a step back in his comeback from control problems, allowing five runs in 2 1-3 innings despite not giving up a hit. He walked five batters and hit another with a pitch.

• Athletics 7, White Sox 0: At Chicago, Jason Giambi hit a three-run homer and Brett Anderson pitched seven impressive innings, sending the Athletics to a victory over the White Sox.

Aaron Cunningham added a two-run shot in the ninth for Oakland, which won the final three games of the four-game series.

With top prospect Gordon Beckham making his major league debut at third base, the White Sox were shut out for the major league-worst eighth time this season, twice with Mark Buehrle (6-2) on the mound.

Beckham went 0 for 3 with a strikeout. He hit into a fielder's choice in his first at-bat.

Anderson (3-5) won for third time in four starts, giving up five hits and striking out four. Oakland has started four rookies in a row for the third time in team history, the last coming in June 1996.

• Rays 3, Royals 2: At St. Petersburg, Fla., B.J. Upton hit a go-ahead two-run homer in the eighth and James Shields allowed two runs over eight innings as the Rays completed a three-game sweep by beating the Royals.

Upton's two-out shot off Jamey Wright (0-2) made it 3-2. The homer helped the Rays overcome an 0-for-13 performance with runners in scoring position.

Shields (5-4) gave up six hits and had eight strikeouts. He has won two consecutive starts, allowing four runs over 15 innings.

Carl Crawford also homered for the Rays, who have won five of six following a season-high five-game losing streak. J.P. Howell pitched the ninth for his second save.