Lefty Barry Zito continues a resurgent season Wednesday when the San Francisco Giants visit Minute Maid Park for the second of three games with the host Houston Astros.

A first-round pick of the Oakland Athletics in 1999, Zito debuted in the majors a year later and was an instant hit, winning 17 games in his first full season in 2001 and as many as 23 a year later in 2002.

He won 15 games with the Athletics in 2006 before signing with San Francisco with a huge free-agent deal and immediately slumped below .500 - 11-13, 10-17 and 10-13 - in his first three seasons in the National League.

He won just 12 games in 2010 and 2011 combined, but climbed back to double- digit wins this year with a 5-2 defeat of the Atlanta Braves on Aug. 23 after allowing two runs on five hits in eight innings.

Zito is 3-3 in seven career starts against the Astros.

He's opposed by rookie Dallas Keuchel, who looks for a first win since his second major-league start on June 23.

The 24-year-old Oklahoma native tossed a complete game while beating Cleveland, 8-1, but has since lost six straight decisions across nine starts - in which the Astros are 1-8.

He fell to 1-6 on the season with a 13-5 loss at St. Louis in his last outing on Aug. 23, when he was shelled for six runs on five hits in four innings.

Keuchel has never faced the Giants.

On Tuesday, Joaquin Arias scorched a game-tying pinch-hit double in the ninth inning and scored the go-ahead run as the Giants took a 3-2 triumph over the Astros.

The Astros took the lead in the eighth when San Francisco starter Matt Cain uncorked a wild pitch with a runner on third, but the Giants battled back in the ninth, as Brandon Belt singled off Wesley Wright before Arias entered as a pinch-hitter to face Wilton Lopez (5-3).

Arias ripped a double down the third-base line to score Belt from first and pinch-hitter Hector Sanchez followed two batters later with a looping single into shallow center field to score Arias for a one-run lead.

"It goes to show you how important the bench is," Giants manager Bruce Bochy said. "They delivered tonight."

Sergio Romo retired the Astros in order in the ninth to record his seventh save of the season, while Santiago Casilla (5-5) recorded the final two outs of the eighth to earn the victory.

Angel Pagan doubled and added a solo shot for the Giants, who won for the sixth time in their last eight games.

Brett Wallace registered three of Houston's six hits and Fernando Martinez clubbed a solo home run, but the Astros lost for the 10th time in their last 11 tries.

The Giants won five of the initial six games between the teams in 2012, taking two of three in a series in June and sweeping another three-game set in July. Houston won the series in 2011, four games to three.