Paul Maholm pitched into the ninth inning and the Chicago Cubs beat Houston, 4-0, in the opener of a three-game set.

Maholm (5-6) controlled the game for the first eight innings, only allowing four Astros to reach base. However, after giving up a pair of hits and running his pitch count to 98, his day ended with one out in the ninth.

"You just have to go out there confident with your game plan, keep the ball down and be aggressive" Maholm said. "If you're kind of doubting your pitches or doubting whatever, you're not going to be as crisp. So, whether I was throwing the so-called correct pitch, I was aggressive with it."

The 30-year-old left-hander ended up allowing four hits and a walk, while striking out six en route to his first win since May 9.

"He was throwing everything for strikes," Cubs catcher Steve Clevenger said. "He had everything. His back-door cutter, he was throwing inside, keeping them off everything away, his changeup was awesome today and his fastball command was great."

Maholm was 0-4 with a 6.43 earned run average in his last eight starts heading into Friday, but he finished two outs short of his fourth career shutout.

Luis Valbuena, Clevenger and Alfonso Soriano hit home runs for the Cubs to account for all four of their runs. For Clevenger, it was his first career blast.

Bud Norris (5-5) came off the disabled list on Friday and took the loss. He gave up all four runs on seven hits and a walk over six innings.

"I thought he battled pretty well," Houston manager Brad Mills said.

Valbuena gave the Cubs the lead in the second inning. With two men gone, he smoked a 2-0 fastball over the left-center field fence.

After a Bryan LaHair single in the fourth, Clevenger pulled a slider over the left-field fence.

"It was a really bad slider," Norris said. "It just hung. I didn't really get comfortable with my slider early today and it definitely showed. I was ahead in the count, that's what makes it even harder, when I'm ahead 1-2 I'm trying to put a guy away and I made a really bad pitch and he made me pay for it."

Soriano capped the scoring with a mammoth sixth-inning home run that left Wrigley Field. Norris threw a low fastball that Soriano went down and deposited well over the fence in left-center.

The Astros chased Maholm in the ninth after a Carlos Lee ground-rule double put men on second and third with one out. Carlos Marmol struck out J.D. Martinez, but then hit Chris Snyder with a pitch. Chris Johnson lined out to give Marmol his sixth save of the year.

Game Notes

Cubs outfielder Tony Campana, who came on to pinch run in the eighth inning, stole his major league-leading 25th base of the season...Maholm made his 200th career start. When going six innings or more, Maholm is 5-1 with a 2.64 ERA (17 earned runs in 58 innings)...The Cubs are 21-15 in 36 games in which they scored four or more runs...The Cubs won their first game against the Astros this season after being swept in a three-game set from May 21-23...Houston has been shut out seven times this season and four times in June...The Astros snapped a six-game homer streak...Norris, who had 81 strikeouts in 73 innings coming into the game, only struck out one...Both teams left six runners on base.