Villanueva entered the game with two runners on and already four runs scored in the third inning, after starter Marco Gonzales lasted just 2 2/3 innings. Villanueva struck out Michael Taylor to keep the score 4-0 and then cruised for three more innings of scoreless ball.
"I knew I was going to try to go multiple innings there, just keep the game where it was," Villanueva said. "The way we've been playing, the way we've been scoring runs in bunches, you kind of feel like the boys are going to come back."
With Villanueva righting the ship, the Cardinals scored three in the third and two more in the eighth to tie it, setting up Brandon Moss' game-winning homer in the ninth.
Villanueva retired 10 of the 11 batters he faced, striking out six.
It's even more remarkable considering that Villanueva hasn't pitched since Aug. 21 and has only pitched twice in the last 16 days.
"He's done that all season," manager Mike Matheny said. "It is more difficult when you're not getting the consistent work, you don't know how long you're going to be put on the shelf, and he's been put on the shelf for a while. And he comes in and he's very sharp. Right from the first batter he faces, he comes into trouble, helps Marco get out of an inning and sails."
Villanueva credits experience with helping him maintain his edge.
"It's not like they don't want to use me," Villanueva said. "It's just there hasn't been a chance, which is a good thing. If I'm not in there, it means the starters are going well and we're winning ballgames."
Joe Harris is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.