SAN FRANCISCO — Tim Lincecum ran his career-best scoreless innings streak to 23 in winning his third straight start and also scored the first run in the San Francisco Giants' 9-0 victory over the Houston Astros today.

The reigning NL Cy Young Award winner struck out nine and allowed three hits with two walks in seven innings. Brandon Medders and Merkin Valdez each pitched an inning to finish the three-hit shutout, the Giants' majors-best 11th and fourth in their last seven games.

San Francisco had 12 hits a day after producing a season high in runs and pounding 15 hits in a 13-0 victory Friday night.

Pablo Sandoval singled home Lincecum in the fifth and Randy Winn added a two-run double and scored on a passed ball in the inning that got by Astros catcher Ivan Rodriguez. Aaron Rowand added a two-run single and Bengie Molina an RBI double.

Lincecum (9-2), expected to be named an All-Star on Sunday for the second straight year, outpitched former Giant Russ Ortiz (3-4). Lincecum struck out Michael Bourn looking on his third pitch of the game. After Lance Berkman doubled to start the fourth, Lincecum struck out the side.

He has gone 18 consecutive innings without allowing a baserunner past second.

Lincecum — coming off back-to-back complete games — walked in the fourth and later scored, then drew another free pass in the fifth to load the bases before Rowand's single. Winn doubled and Sandoval was intentionally walked before Ortiz's day was done. He received a warm ovation as he walked off the mound.

Lincecum's scoreless streak is the longest by a Giant since Robb Nen went 25 2-3 consecutive innings without allowing a run in 2000. Lincecum has won six of his last seven decisions.

The Astros were shut out in consecutive games for the second time this year, also April 12-13 at St. Louis and Pittsburgh. The Giants shut out Houston in back-to-back games for the first time since Sept. 22-23, 1993.

Ortiz struck out a season-high seven but lost his second straight decision and saw his winless stretch reach six starts.

He was a former fan favorite during six seasons covering two stints with San Francisco, last in 2007. He was the Giants' Game 6 starter in the 2002 World Series when the club collapsed and lost in seven games to the wild-card Angels.

The right-hander was a fourth-round draft pick by the Giants in 1995 and went 69-47 during his time with San Francisco. This marked his eighth appearance against his former team — and he is 0-4.

NOTES

Lincecum went 16 scoreless innings last season. ... He is 2-0 in five career starts vs. Houston and has never allowed a home run to the Astros. ... The Astros are 14-10 in day games. ... Houston is 15-7 against the NL West. ... A home-plate ceremony was held before the game on the 70th anniversary of Lou Gehrig's luckiest man speech, and nine fans from the Bay Area with ALS — the disease Amyotrophic Lateral Sclerosis that ended Gehrig's career and ultimately his life — gathered on the field to commemorate the anniversary. The Giants also remembered longtime fan Frank Ratto, who died of the disease 2006.