San Francisco (50-67) at Houston (59-59)

When San Francisco Giants pitcher Tim Lincecum broke into the major leagues last spring, comparisons between him and Houston Astros ace Roy Oswalt were common.

A little more than a year later, it’s hard to deny that Lincecum has the edge between the two.

Lincecum looks to continue his remarkable sophomore season as he takes the mound against Oswalt and the streaking Astros on Tuesday night at Minute Maid Park.

Lincecum (12-3, 2.68 ERA) made his major-league debut last May 6, immediately drawing comparisons to Oswalt (9-8, 4.56) because of similarities in their deliveries, their abilities to reach the upper 90s with their fastballs despite their relative small frames and their overall effectiveness.

The 5-foot-11, 170 -pound Lincecum, however, has had more success than his 6-foot, 185-pound counterpart this season. Though he’s pitching for a Giants (50-67) team that ranks among the worst in the majors offensively, he’s tied for sixth in the NL in wins while leading the league in ERA and strikeouts (175).

Those statistics have convinced Giants center fielder Aaron Rowand that Lincecum should be the 2008 NL Cy Young Award winner despite the team’s struggles.

“All you have to do it take a look at his numbers,” Rowand said after Lincecum held Atlanta to two runs and five hits while striking out eight in eight innings of a 3-2 victory Wednesday. “With the exception of one, maybe two starts, all season long he’s been dominating.

“You talk to guys on the other team that have to face him and all of them are pretty impressed with the way that he’s developed, not only with his pitches but his maturity and learning how to pitch. He’s not a thrower.”

Oswalt, a top-five finisher in Cy Young voting in five of his seven seasons, likely won’t be considered strongly for the award this year. His ERA and his winning percentage are both easily career worsts, and the right-hander has given up 155 hits in 134 1-3 innings.

The Astros (59-59), however, haven’t lost confidence in Oswalt, who limited Cincinnati to one run in seven innings of a 7-4 victory Thursday.

“He’s been our ace for a while,” Astros first baseman Lance Berkman said. “It’s always a good feeling when he’s pitching.”

Oswalt hopes to help Houston match its season high with its sixth straight win and get the club over .500 for the first time since June 10. Since falling into last place in the NL Central on July 23, the Astros have won 13 of 17, a hot streak that continued when Ty Wigginton drove in all of the team’s runs in a 3-1 victory in Monday night’s series opener.

Wigginton also fared well defensively in his first start in the outfield since October 1, 2006, making a putout on the one fly ball that came his way. He figures to spend a lot of time in left field in place of Carlos Lee, who’s likely out for the season after undergoing surgery on a broken left pinkie finger Monday.

“It was fine,” Wigginton said. “It’s not like I got a whole lot of action, either.”

Lincecum has squared off against Oswalt twice in his three career starts against Houston. The aces met in Lincecum’s third and fourth career starts May 17 and 22, 2007, and Lincecum went 1-0 with a 1.20 ERA and 14 strikeouts in 15 innings in those games - both Giants victories.

Oswalt, who’s 3-5 with a 3.99 ERA in 11 career starts against San Francisco, went 0-1 with a 2.57 ERA when matched up with Lincecum.