(Sports Network) - The Pittsburgh Pirates hope to build off Monday's much- needed victory over the Houston Astros when the two National League Central members resume a three-game set tonight at Minute Maid Park.

The Pirates appeared headed towards a sixth consecutive loss in yesterday's series opener, but the club erupted for seven runs in the top of the ninth inning to rally for a 9-3 victory. Adam LaRoche highlighted the comeback by belting a tie-breaking two-run homer with one out in the frame.

Jason Bay tied the contest at 3-3 with a solo home run off Astros closer Jose Valverde, and Xavier Nady followed with a single before LaRoche socked Valverde's offering over the left-field wall.

Jack Wilson later delivered an RBI single to give the Bucs a 6-3 lead, and Freddy Sanchez capped the huge inning with a three-run inside-the-park homer.

Sanchez finished with three hits and four RBI on the evening, while Bay went 4-for-5 and knocked in two runs to add to Pittsburgh's 18-hit attack. Reliever Tyler Yates was credited with the win after holding Houston scoreless in the bottom of the eighth.

Valverde (4-3) was charged with six runs allowed and surrendered five hits while recording just one out in the ninth.

Carlos Lee had two hits and two RBI for the Astros, who had won four of five coming in. Houston starter Runelvys Hernandez gave up just two runs on eight hits over an effective 5 1/3 innings.

Pittsburgh tries to make it two in a row tonight behind Paul Maholm, but the lefty may have to improve on his previous effort for that to occur. Maholm struggled through six innings last Thursday in Colorado, allowing five runs on eight hits to suffer the loss in a 5-3 Pirates' setback.

The former first-round pick was much sharper in his final outing before the All-Star break, when he held the New York Yankees to two runs over eight innings to lead the Pirates to a 4-2 win on July 10. In fact, Maholm had gone 2-0 with a 2.40 earned run average over a four-start stretch prior to the Colorado game.

Maholm does own a victory over the Astros this season, which came in Pittsburgh on June 5. He gave up just three runs -- two earned -- and did not walk a batter in eight innings during that 4-3 win.

The 26-year-old is 4-3 with a 5.55 ERA in eight lifetime starts against Houston.

With ace Roy Oswalt recently placed on the disabled list, the Astros will call up Jack Cassel from Triple-A Round Rock to take the mound this evening. The right-hander made two starts and a pair of relief appearances with the big club earlier this season and went 1-0 with a 6.28 ERA over a combined 14 1/3 innings.

Cassel has had greater success in the minors this year. In 12 games (10 starts) with Round Rock, the 27-year-old is 6-1 with an excellent 1.92 ERA and allowed just four home runs in 65 2/3 innings.

In his only career matchup with the Pirates, Cassel earned his first major league win by tossing six shutout innings on September 17 of last season. He was a member of the San Diego Padres at the time.

Pittsburgh has now won five of its last six meetings with the Astros and is 7-3 at Minute Maid Park since the start of last season. The Pirates are also 15-7 against Houston since the beginning of the 2007 campaign.