updated 9:50 p.m. ET June 4, 2009

WASHINGTON - The emotions finally flowed for Randy Johnson when the final out was made.

A hug for his son, who was serving as batboy. Hugs for every teammate, plus a really big one for his manager. The game ball presented to his wife as his three daughters beamed with pride. A news conference that lasted a half-hour from a player who usually doesn’t have much to say. Someone even spotted a smile.

The Big Unit admits he can come across as surly, and he did his best over the past few weeks to downplay his pursuit of 300 wins. Once he got there — with a steady, six-inning performance in the San Francisco Giants’ 5-1 victory over the Washington Nationals in the opener of a doubleheader Thursday — he was free to express that, yes, it really is a big deal.

“I think it kind of hit me when I walked on the field,” Johnson said. “It’s a long-range achievement. It’s not a one-game or a one-year achievement, it’s a career achievement. Who knows how many teammates I’ve had over my 21 years, but they had a great deal to do with my success. I’m going to think about this for a long time.”

In the nightcap, the Giants completed a sweep 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.

Johnson became the 24th pitcher to reach the 300-win milestone, and he did it as a mature pitcher, not the overpowering tangle of arms and legs who was all about strikeouts early in his career. He walked two, struck out two, allowed only an unearned run and threw 50 of his 78 pitches for strikes. He faced four batters above the minimum and got shutout relief from his bullpen.

“I get more gratification out of that because of the way I’m doing it now than the way I did it 10 years ago,” Johnson said.

It was hardly the ideal setting for a historic moment. The crowd was small and the weather was wet. Some of the few thousand fans who witnessed the feat — the Nationals have trouble drawing a crowd for anything these days — chanted “Randy! Randy!” in the bottom of the ninth, and he tipped his hat to them all.

Family and friends from all over flew in for the occasion to see Johnson (5-4) become the first pitcher to get 300 on his first try since Tom Seaver in 1985.

“He’s become one of the dinosaurs with the other 23, and he didn’t want to make a big deal out of it,” Giants manager Bruce Bochy said. “But you could see after the game — I’m sure he’s had his eye on this 300 for a while. He’s done an incredible job with keeping his self in shape, pitching at 45 and still throwing the ball the way he’s throwing is quite an accomplishment.”

Johnson had to leave the game because of what he called a “senior moment” — his decision to go after a comebacker that he knocked down in the sixth inning. The 6-foot-10 Johnson barehanded the ball while falling forward to throw out the runner and bruised his pitching shoulder on the play. He’s expected to make his next start.

San Francisco led 2-1 when Johnson departed, but he 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.

The 45-year-old Johnson is the sixth left-hander to win 300 games and 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.

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Tony Gutierrez / AP

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