A day after Tim Lincecum outdueled Roy Halladay in a marquee matchup of aces, Oswalt beat Jonathan Sanchez.
The series shifts to San Francisco for Game 3 on Tuesday afternoon. Matt Cain faces Philadelphia's Cole Hamels, the 2008 World Series MVP.
Even though he didn't finish the outing, it sure was a complete game for Oswalt. He allowed one run and three hits, striking out nine. He also singled and scored a run after racing through a coach's stop sign in the seventh.
"I didn't see it until I got halfway down the line," Oswalt said of the sign. "I was hoping I would be able to get in there."
Cody Ross hit his third solo homer in two games for the Giants.
Rollins busted out of a 1 for 15 postseason slump, going 2 for 3 with a bases-loaded walk and a bases-clearing double.
Sanchez, a former Augusta GreenJacket, gave up three runs -- two earned -- and five hits in six-plus innings. The tough lefty had dominated the Phillies in his five previous starts against them, not allowing more than four hits in any outing.
Oswalt didn't allow a hit until Ross connected with one out in the fifth to tie it at 1. He ripped a 1-0 pitch into the left-center field seats -- nearly the same spot both of his homers off Halladay landed.
Acquired from Houston on July 29, Oswalt went 7-1 with a 1.74 ERA in 13 games with the Phillies. Oswalt was Philadelphia's best pitcher down the stretch.