The Cubs proved they’re just as adept at scoring runs with small ball as they are swinging away.Ryan Theriot bunted in the go-ahead run in the seventh inning, and Derrek Lee capped a six-run uprising with a three-run homer that sent the Cubs to a 7-2 victory over the scuffling Houston Astros on Friday.Theriot was retired easily his first three at-bats before coming to the plate with the bases loaded and one out in the seventh. He laid down a bunt toward Pedro Feliz, and the ball seemed ready to roll foul when the first baseman tried to make a play. It squirted away and everyone was safe, giving the Cubs a 3-2 lead.Kosuke Fukudome followed with a sacrifice fly, and Lee drove Jeff Fulchino’s 3-2 pitch over the left-field wall to put the game away. It was the Astros’ ninth loss in 10 games, and they’ve still scored only 21 runs — by far the fewest in the majors.Carlos Silva (1-0), making his first home start at Wrigley Field, was the beneficiary of the Cubs’ late surge. He allowed five hits, two unearned runs and no walks in seven innings.Acquired in December from Seattle for Milton Bradley, the ineffective and injury-prone Silva had been a $48 million flop in two seasons with the Mariners.Silva helped himself in the first inning with a run-scoring double — his first double and his first RBI since Aug. 25, 2003, when he was with Philadelphia. It was just his fourth career hit and first in nearly four years.Later, Silva kept his cool after two mistakes in the fourth inning involving Fukudome that helped Houston take a 2-1 lead. Marlon Byrd came over from center and called for Hunter Pence’s fly into the gap, but Fukudome also tried for the catch and knocked the ball out of hiss glove. The right fielder then failed to catch Chris Johnson’s sinking liner and the ball skipped all the way to the wall for an RBI triple. Fukudome said he should have yielded on the play.Silva gave up Tommy Manzella’s RBI single, but rebounded to strike out Quintero and was in command the rest of the way.Byrd started the seventh inning with a double off Felipe Paulino (0-1) and scored on Alfonso Soriano’s double. Paulino then walked the bases loaded, leading to the cascade of runs.Carlos Lee singled in the sixth to snap a career-worst 0-for-18 slump, but Houston’s $100 million cleanup hitter — who has averaged 109 RBI the last seven seasons — is still hitting just .103 and has yet to drive in a run.Soriano in left field and third baseman Aramis Ramirez robbed Lee of hits his first two times up, and he was visibly frustrated after striking out in the eighth.

NOTES—The Cubs have homered in their last 20 games against the Astros, the longest streak against one team in franchise history….Berkman, on the DL after arthroscopic knee surgery March 13, is expected to make his first rehab appearance Saturday at Triple-A Round Rock. He could return to Houston’s lineup Tuesday…..Astros RHP Sammy Gervacio (sore shoulder) is scheduled to pitch a rehab outing Monday at Round Rock…..Ted Lilly (shoulder surgery) will make one more rehab start, Monday at Class A Peoria, before returning to the Cubs’ rotation the following week.