Alfonso Soriano hit his 34th career leadoff homer to back Marquis' three-hit shutout and lift the Cubs to a 1-0 victory over the Pittsburgh Pirates.

"What perfect timing for a complete-game shutout," Cubs manager Lou Piniella said. "He really pitched well. He was throwing just as hard in the ninth as he was when he started the ballgame. It was an outstanding effort. We needed it. Our bullpen was really spent."

The Cubs had exhausted the relievers in a 15-inning, 4-3 loss to the Pirates on Tuesday night. Marquis struck out five and did not walk a batter, collecting his first complete game since Sept. 4, 2005, against Houston.

It was the first time a Cubs pitcher went the distance since Rich Hill did so last Sept. 22, when he notched a rain-shortened five-inning complete-game win against Cincinnati.

"You obviously know the situation when the bullpen's a little fatigued doing the extra-inning games, but you try not to put added pressure on yourself," Marquis said. "You've just got to still take the same mentality and go as long as you can for as hard as you can. If that means going nine, than obviously that's your goal."

Apparently the Pirates couldn't decode Marquis after facing him May 2 at PNC Park. In that game, he held Pittsburgh to one run on four hits over eight innings. On Wednesday, Marquis (5-1) retired the first 16 batters he faced before Don Kelly singled with one out in the sixth.

"My goal is to win ballgames, not throw a no-hitter," Marquis said.

The right-hander also served up a two-out double to Ryan Doumit in the seventh and a one-out single in the eighth to Jose Bautista.

"I try to stick to a game plan," Marquis said. "I try to execute pitches, and until the hitters show me they can do something with it, I'm going to stay with that plan."

One of the Cubs' free-agent acquisitions this offseason, Marquis was as strong in the ninth as he was when he began the game. He has produced quality starts in six of his seven starts, and is holding batters to a .175 average. This is a guy who led the National League in losses in 2006 with 16.

"This stretch of games to start the season for myself has been as good as I've been throughout my career," he said. "I feel like my delivery is as consistent as it's ever been. I feel like I'm repeating the same delivery over and over again, and that's the reason -- I really believe -- for this success."

Give Cubs pitching coach Larry Rothschild credit. He started working with Marquis this offseason, before the team signed the right-hander to a three-year deal. It's paying off.

"He was awesome," Cubs outfielder Jacque Jones said of Marquis.

Jones wasn't. The only left-handed bat in the Cubs lineup against Tom Gorzelanny (4-2), Jones batted eighth for the first time this year, and was 0-for-4, stranding nine baserunners.

"I left the world on base. Everybody knows I left the world on base," Jones said. "I want to do whatever I can. I'm going to go through stretches like this -- everybody is going to go through stretches like this. It's just the way it is."

He did hit the ball hard in his last two at-bats. Piniella stuck with him.

"He shows way more confidence than everybody else does," Jones said of the Cubs manager. "That's all that matters. As long as the manager has confidence in me, and shows faith in me, it really doesn't matter what everybody thinks. He knows I can play. I know I can play. Eventually it will come through."

The win was the Cubs' sixth in their last seven games, and the 19th quality start by a Chicago pitcher in 31 games.

Soriano gave Marquis all he needed when he belted his third homer of the year and second leadoff homer this season off an 0-1 pitch from Gorzelanny. The blast also extended Soriano's hitting streak to a career-high 17 games. His previous best was 15 games, done three times.

"The key of the game tonight was Marquis," Soriano said. "He pitched a very good game."

"You never think it'll be 1-0 after the leadoff hitter hits one out of the ballpark," Piniella said. "Jason made it stand up. You could tell he had good stuff in the middle part of the ballgame. He just finished it. He finished it in convincing fashion. His stuff wasn't going down. He was maintaining it."

Speaking of streaks, Derrek Lee kept his alive as well. Lee singled to lead off the Chicago fourth to extend his hitting streak to 16 games. The National League's leading hitter has also reached base safely in all 31 games.

Now, the Cubs need to get everybody going.

"You have to believe, and I do, that these kids are going to hit," Piniella said. "We're just not hitting at opportune times in some of the games we're playing in. It's a contagious thing. If we can get one or two guys going in that regard, you'll see we'll get three or four. Once you get to that, believe me, it becomes a team thing. We have to keep playing and hope it happens quickly."