Chicago, IL -- (Sports Network) - Alfonso Soriano's game-winning RBI single in the ninth salvaged the Cubs' 5-4 victory over the Astros.

Kevin Gregg blew a four-run lead in the top of the ninth, but LaTroy Hawkins (1-1) opened the bottom half with a walk to Bobby Scales, who moved up a base on a sacrifice bunt and sprinted home for the winning run on Soriano's base hit to right.

Sean Marshall (2-2) was credited with the win, Chicago's fifth straight. Micah Hoffpauir went 2-for-3 with a two-run homer for the Cubs, whose starter, Randy Wells, yielded just four hits and three walks in six scoreless frames.

"Wells has pitched two outstanding games," Cubs manager Lou Piniella said. "He still doesn't have a win, but if he continues to pitch like that, he will win quite a few games."

Carlos Lee went 3-for-4 with a home run, while Lance Berkman had two hits and homer in the loss, the club's second in seven games. Roy Oswalt gave up three runs on six hits while striking out seven in a six-inning start for Houston.

Berkman and Lee started the ninth-inning rally with back-to-back homers off Gregg, who then allowed a pair of singles before plunking Geoff Blum to load the bases, prompting his swift exit.

Aaron Heilman entered and yielded a two-run single to Ivan Rodriguez, and Michael Bourn worked a two-out walk to load the bases later in the frame.

Marshall came in from the bullpen and induced an inning-ending groundout by Berkman, and the Cubs pulled out the roller-coaster win in the bottom half.

Wells got out of a bases-loaded jam in the second, ending the frame with an inning-ending ground out from Oswalt, who retired 15 of 18 leading up to the sixth inning.

Soriano opened that frame with a single and moved into scoring position on a sacrifice bunt. After a fly out from Kosuke Fukudome, Derrek Lee broke a scoreless tie with a run-scoring single to left.

Hoffpauir then stepped in and drove a 2-1 slider over the right field wall for a 3-0 lead.

Chicago's Angel Guzman hurled a perfect seventh, and Carlos Marmol followed by striking out the side in the eighth.

Geovany Soto padded the 3-0 lead with an RBI single in the bottom half.

Game Notes

Friday's opener of this scheduled three-game set was postponed due to inclement weather. It has been rescheduled for Thursday, July 30 at 2:20 p.m. (et.)...In his first career start on May 8, Wells threw five scoreless innings against the Brewers...Oswalt came in 12-12 with a 3.88 ERA in 27 career games (26 starts) against Chicago...Chicago leads the season series, 5-1.