BOSTON (AP) -- David Ortiz solved Michael Wacha's postseason spell, hitting a two-run homer over the Green Monster and the Boston Red Sox led the St. Louis Cardinals 2-1 after six innings Thursday night in Game 2 of the World Series.
The Red Sox were trying for their 10th straight Series win and a commanding 2-0 lead in this matchup.
Wacha had already extended his scoreless streak to 18 2-3 innings - a record for a rookie in a single postseason - before Ortiz tagged him in the sixth.
A day after Ortiz homered after nearly hitting a grand slam earlier in an 8-1 romp, Big Papi delivered again. He connected for his fifth home run of this postseason and 17th of his career.
Dustin Pedroia drew a one-out walk and, with the Fenway Park crowd on its feet, Ortiz hit a full-count changeup over the wall in left-center field for a 2-1 edge. Ortiz acknowledged his faithful fans, emerging from the dugout for a curtain call.
It was just Boston's third hit off Wacha, the 22-year-old who had been dominating every team he'd faced in October. Wacha slammed his glove onto the bench when the inning ended.
Red Sox starter John Lackey worked around four hits in slowing the Cardinals. He pitched a day after turning 35 - it was his first Series start since 2002 when, as a rookie for the Angels, he beat Barry Bonds and San Francisco in Game 7.
Matt Holliday lined a leadoff triple into the oddly configured triangle in center field in the fourth and scored on Yadier Molina's chopper.
The Cardinals' 1-0 lead marked the first time they'd been ahead of the Red Sox in October for quite a while. Boston never trailed while sweeping St. Louis in the 2004 Series, and was ahead from the beginning Wednesday night.
Carlos Beltran started for the Cardinals in right field, returning from an injury that forced him out of the opener. Beltran exited in the third inning and went to a hospital, shortly after bruising his ribs when he rammed into the short bullpen wall while taking away a grand slam from Ortiz.
Both teams made changes to their lineups.
Cardinals manager Mike Matheny benched shortstop Pete Kozma after making two errors in the opener and put Daniel Descalso in his place. Jarrod Saltalamacchia replaced David Ross as Boston's catcher.
The teams are off Friday, and resume with Game 3 at Busch Stadium on Saturday night. Boston starter Jake Peavy makes his Series debut against Joe Kelly.
After the Cardinals played a most sloppy game in the opener, Wacha restored early order to the NL champions.
The right-hander flashed a 95 mph fastball and a diving changeup while holding Boston hitless until Jacoby Ellsbury's broken-bat bloop single with two outs in the third.
No one in the Boston lineup had ever hit against Wacha and it showed, as the Red Sox struck out four times in the first three innings and took a lot of weak, awkward swings.
The Cardinals had seen this already from Wacha, even though he made only nine regular-season starts. He began the night with a 3-0 record in three postseason starts, allowing just eight hits while striking out 22.
Wacha had his own cheering section at chilly Fenway Park, too. His mom, dad and younger sister bundled up in the stands after arriving from Texarkana, Texas.