(My Sportsbook) - California-born left-hander Randy Wolf can stay unbeaten during his brief stint with Houston tonight, when the Astros host the San Francisco Giants in the third game of a four-game series at Minute Maid Park.

The Astros enter the game in the middle of the pack in a crowded National League Central Division, having won six straight games to climb above .500 at 60-59 overall and within 12 games of the first-place Chicago Cubs.

The Giants, meanwhile, are fourth in the NL West, trailing the Arizona Diamondbacks by an only slightly less daunting 9 1/2 games in spite of being 18 games under .500 at 50-68.

Wolf, who was acquired from the Padres shortly before the trade deadline, is 1-0 in three starts with his new club, allowing 20 hits and seven earned runs in 15 1/3 innings while walking eight batters and striking out 16.

He was 6-10 with a 4.74 ERA in 21 starts with the Padres after making just 18 starts with the Los Angeles Dodgers in 2007 and 12 with Philadelphia in 2006 due to myriad arm injuries.

He allowed nine hits and three runs over 12 innings in two starts against the Giants -- both no-decisions -- earlier this season with San Diego, and is 5-4 with a 3.80 ERA in 12 lifetime starts against San Francisco.

Another recently traveled left-hander, Barry Zito, gets the call for the Giants in search of consistency.

The second-year National Leaguer has alternated wins and losses in his last four starts and is 4-5 with a no-decision in his last 10 starts stretching back to June 13.

He tossed an eight-inning masterpiece, allowing three hits over eight scoreless innings, en route to a 2-0 win at San Diego on August 2, but was touched for six hits and five runs in five innings of a 6-2 loss to the Dodgers six days later.

He allowed seven hits and three runs in a start against Houston earlier this season while getting a no-decision, and is 1-0 in two career starts against the Astros while combining to allow 11 hits and four runs in 13 innings.

On Tuesday, Lance Berkman hit a grand slam as part of an eight-run seventh inning for Houston, which took a 12-4 win over San Francisco.

Darin Erstad had two hits, including the go-ahead two-RBI single, and Miguel Tejada added three hits and an RBI as the Astros extended their winning streak to six, tying a season-high.

Roy Oswalt (10-8) won his fourth consecutive decision, throwing seven strong innings. He gave up three runs and 10 hits and three walks, while fanning four in the victory.

Tim Lincecum was throwing a gem before being struck in the right knee by a line drive, forcing him to leave in obvious pain. He threw 4 1/3 innings and gave up two runs -- one earned -- and only one hit while striking out seven and walking two.

Tyler Walker (4-7) failed to record an out in facing two batters, and allowed both to score on one hit to earn the loss.

Fred Lewis went 3-for-5 with a run scored while Randy Winn drove in two runs in the Giants' third defeat in five games.

Houston won three of four when these two clubs met in San Francisco from May 12-15.