WASHINGTON -- What a difference two starts made for Shairon Martis. Against the Phillies on Monday night, Martis had a tough time throwing strikes and gave up seven earned runs.

On Saturday afternoon, however, Martis pitched the game of his Major League career and helped the Nationals defeat the Cardinals, 6-1, at Nationals Park.

The right-hander threw a complete game and gave up one run. It was the first nine-inning complete game by a Nationals pitcher since Pedro Astacio went the distance against the Braves on Aug. 15, 2006. It was also the first by a Washington hurler at Nationals Park.

Martis' only blemish was giving up a solo home run to Colby Rasmus in the seventh inning. Before the home run, Martis was nearly perfect. In fact, he didn't give up a hit for 4 2/3 innings, and allowed just five hits and no walks overall, while striking out six.

The Nationals gave Martis the lead by scoring four runs in the fifth inning off right-hander Joel Pineiro. After Martis reached on an unsuccessful sacrifice bunt, Cristian Guzman singled him to third, then Nick Johnson drove him in with a sacrifice fly to give the Nationals a 1-0 lead.

With two outs, the next batter caught a break. Ryan Zimmerman popped up to first baseman Chris Duncan, who dropped the ball in foul territory. Zimmerman, who had already extended his hitting streak to 21 games in the first, then singled to center to put runners on first and second. Adam Dunn was the next hitter, and he hit a three-run homer.

"It was big for us and a little confidence boost," Dunn said.

Martis looked at the scoreboard in the fourth and noticed he hadn't given up a hit, but knew right away he would give it up eventually. It came in the fifth inning, when Yadier Molina singled up the middle.

"Once I saw I was throwing a no-hitter, you knew they were going to break it up," Martis said. "When you don't know, you are going to throw a no-hitter. That's when it's going to happen."

Martis said this was his best start since throwing a seven-inning no-hitter against Panama in the World Baseball Classic. He was pitching for the Netherlands at the time.

"It was the same," Martis said when asked to compare the two games. "I only threw seven innings because of the mercy rule. If there were no rules, I would have thrown a complete game."

Asked why he was so much more effective against the Cards than in his previous start, Martis said, "Today, I was more aggressive. ... After the second inning, I knew I had good stuff. My fastball had good life, changeup was excellent, the slider was good. Today was the day."

Manager Manny Acta is usually cautious when it comes to young starting pitchers. Sometimes, he will take them out of a game after seven innings so they could leave on a positive note, even if they are still pitching well. In the case of Martis, Acta never thought about relieving him. It helped that Martis had his 92-mph fastball throughout the game.

"Even in the seventh inning, I told Randy, 'Hey, right now he still has [better] stuff than anyone we were going to bring out of the bullpen.' He kept his velocity the whole game. It was still 92 miles per hour at the end," Acta said. "There was no doubt in our minds. I'm glad he got the second out in the ninth inning with [Ryan] Ludwick. We didn't want to push him to more than 110 pitches. Once we got Ludwick quick, we were going all the way with [Martis]."

It was second baseman Anderson Hernandez who set the tone for the game. Skip Schumaker led off and hit a sharp ground ball up the middle. Hernandez dove, backhanded the ball and threw out Schumaker for the first out of the inning.

"We are a better defensive club than what we are showing right now," Acta said. "We are going to continue to drill these guys, and we will be better for it."

It was in 2007 when Acta first met Martis. Acta went to watch right-hander Shawn Hill pitch for Class A Potomac during a rehab game. Martis was sitting next to Acta charting the game. Just two years later, Martis is pitching for the Nationals.

Unlike teammate Jordan Zimmermann, Martis didn't enter the league with much fanfare, but Acta insists that Martis has fans in the front office.

"Even last year, when he came up, we did some rankings, and we had him pretty high over certain guys," Acta says. "We like the fact that he is a good athlete and can field his position, because that counts for a lot. He can swing the bat, and he can pitch. He is only 22 years old, so it's very encouraging."

In the eighth, the Nats tacked on two runs. Austin Kearns drove in the first with a triple past a diving Rick Ankiel in center field, then Hernandez singled him in.

With the victory, the Nationals improved their record to 6-17.