Wacha, a 22-year-old right-hander, wasn't quite as sharp and allowed two runs, three hits and four walks in six innings with six strikeouts. But he improved to 4-0 in four outings this post-season, matching the regular season wins in his brief career.
"He pitched outstanding," Cardinals catcher Yadier Molina said. "Just one pitch, to a great hitter like Big Papi. We take our hat off to him."
His family made the trip from Texas and sat in the cold to see Wacha, the 19th pick in last year's amateur draft.
The Cardinals' hard-throwing bullpen combined for one-hit relief, with Trevor Rosenthal striking out all three batters in the ninth for a save. He whiffed Daniel Nava with a 160km/h fastball to end it.
All three St Louis pitchers were 23 or younger. "It doesn't surprise me. Those guys got talent," Molina said. "Like I said many times before, they're not afraid to pitch."
Seeking its second World Series title in three seasons, St Louis improved to 7-0 this post-season when scoring first and stopped Boston's streak of nine wins in World Series games.
When the series starts play again tomorrow at Busch Stadium, Jake Peavy starts for the Red Sox and Joe Kelly for the Cardinals. Twenty-nine of the previous 55 teams that won Game 2 to tie the series went on to take the title.
A night after the Cardinals made three errors in the opener and let the Red Sox romp in 8-1, the fielding failures were on the other side.
Given a 2-1 lead, Lackey walked David Freese with one out in the seventh and allowed Jon Jay's single. Breslow relieved, and the Cardinals pulled off a double steal as pinch-runner Pete Kozma swiped third.
It was an unusually aggressive move for the Cardinals, ranked last in the National League this year.
- AP