Center fielder Aaron Rowand, right, and right fielder Cody Ross avoid a potential disastrous collision in the outfield on a second-inning hit by Wilson Ramos. (Rob Carr/Getty Images)

Jason Marquis has a few baseballs stashed in a case at home, keepsakes from the best of his 308 starts in the major leagues. On any given night, he might add another. Friday night, after he wrapped his left arm in bandages and ice, he rested a ball on the top shelf of his locker. On it, in black ink, he had scrawled: “CG Shutout.”

Marquis had pitched one of the best games of his life, the fourth complete-game shutout of his career, a performance that gave the Washington Nationals a 3-0 victory over Tim Lincecum and the defending World Series champion San Francisco Giants. Before 21,399 at Nationals Park, Marquis allowed five hits, walked none and struck out seven.

Marquis himself drove in more runs than he allowed, and the Nationals beat the Giants without getting a hit from the first four batters in their lineup. Laynce Nix and Ian Desmond led the bottom-of-the-order barrage against Lincecum, going a combined 5 for 6, with two doubles from Desmond and a two-run, second-inning homer from Nix.

The Nationals have lost 219 games since the start of 2009, during which time Lincecum has won a Cy Young, clinched a World Series and struck out more batters than any man alive. Therein lies more evidence that you should not wager on baseball, even with Monopoly money: The Nats have beaten the Freak three straight meetings dating from 2009.

“That’s the World Series champion with the strikeout leader pitching against us,” Desmond said. “We just beat them. That says something about us, you know? We’ve got to believe in ourselves. We’re getting there. We’re getting there.”

Marquis asserted himself again as a staff anchor, lowering his ERA to 2.62 in 341 / 3 innings, both best on the Nationals. The Nationals thought they were getting an innings-eating, stabilizing starter two winters ago when they signed Marquis. They had to wait one disastrous year, but they may have gotten something better.

The Nationals have won the past four times Marquis has taken the mound, and all five of his outings this season have been quality starts; only nine pitchers in the majors had five quality starts entering Friday. Marquis needed only 96 pitches to complete the 10th individual shutout of the season; only two other starters this season have wrapped up a shutout in fewer than 100 pitches.

“He just made the game feel real comfortable for everybody in our dugout,” Manager Jim Riggleman said. “He was just extremely sharp, had everything working and we played good behind him. He was in complete control.”

It is early yet, but Marquis is making his injury-plagued 2010 season look like an interruption to a late-career blossoming. He made the 2009 All-Star Game with the Colorado Rockies, before the Nationals signed him to a two-year, $15 million contract. Marquis feels as though he has become more effective throwing his secondary pitches for strikes, which has led to one of the best stretches in his career.

“I felt like I threw this way in Colorado,” Marquis said. “I just feel like I’m getting more consistent as time goes. I’m learning more about myself day by day, start by start. I definitely feel like I am [getting better]. I’m throwing more quality strikes with all my pitches.”

Friday, he kept Giants batters off balance with a vicious break on his sinking fastball and changing speeds with a constant strikes. Marquis does not overpower hitters — he did not throw a single pitch over 92 mph. But he can frustrate them. Marquis struck out the side in the sixth. After Aubrey Huff foul-tipped a change-up into Wilson Ramos’s mitt, Huff flung his bat 30 feet across the turf.

Nix provided Marquis all the offense he needed. He starting in left field in place of Michael Morse because Riggleman wanted Nix’s left-handed bat facing Lincecum. After Ramos doubled, Nix sent a 1-2 slider just shy of the upper deck in right field, giving the Nationals a 2-0 lead and sending Lincecum into a hole out of which his offense, against Marquis, could not bring him out.

“You have to focus in the box,” said Nix, who faced Lincecum for the first time. “He had good stuff tonight, no doubt.”

Marquis helped himself in the fifth. After Desmond singled and stole second, Marquis tomahawked a 93-mph fastball into right-center field for a single that made the score 3-0.

Marquis’s gem continued Lincecum’s bad luck against the Nationals. In 2009, they beat him in the season he won his second Cy Young. Last season, the Nationals sent Luis Atilano to the mound — the very same Luis Atilano whom the Nationals removed from their 40-man roster this offseason and ultimately started in Class AA Harrisburg — and beat Lincecum.

And then, on Friday, perhaps no pitcher could have beaten Marquis, not even Lincecum. That’s something no one expected, which baseball has a way of delivering.