Now, he's headed to his first World Series.
The Giants have All-Star game MVP Melky Cabrera to thank for helping his teammates secure home-field advantage in the postseason — while Cain was the winning pitcher the National League's 8-0 victory in July. Cabrera was suspended 50 games Aug. 15 for a positive testosterone test, then wasn't added to the roster by the Giants after his suspension ended.
After rain fell on the Cardinals during batting practice, the skies turned blue and the weather cooperated. Anxious players on both sides hung over the dugout rails as the game began.
Cain joined St. Louis' Chris Carpenter as the only pitchers with victories in two winner-take-all games in the same postseason. Carpenter, who lost Games 2 and 6 in this series, did it last year.
Cain also pitched the Giants' Game 5 division series clincher at Cincinnati, when San Francisco became the first team in major league history to come back from an 0-2 deficit in a five-game series by winning three consecutive road games.
"I think to do it, the guys actually have to believe it can happen," Posey said.
He delivered on an even bigger stage Monday as San Francisco saved its season once again. The Giants won their 20th NL pennant and reached their 19th World Series.
Cain walked off the mound to a standing ovation when Jeremy Affeldt entered with two outs in the sixth. Affeldt then got Daniel Descalso to pop out with two runners on.
Yadier Molina had four hits but got little help from the rest of the Cardinals, who went 1 for 21 with runners in scoring position over their final three games.
"It's about the team that's hot, and we went on a cold streak," Cardinals manager Mike Matheny said. "We got to this point by being that team that was hot and taking advantage of opportunities. But we just couldn't make it happen these last two games."