Boston broke a 1-1 tie with a pair of seventh-inning runs to support another brilliant outing by starter Jon Lester in a 3-1 victory over the St. Louis Cardinals on Monday that put the Red Sox on the brink of winning the World Series.

The victory gave the Red Sox a 3-2 lead in the best-of-seven and a chance to clinch the Major League Baseball crown with a win at Boston's Fenway Park in Game Six on Wednesday.

A ground-rule double by catcher David Ross plated one run and a single by center fielder Jacoby Ellsbury knocked in another off St. Louis starter and loser Adam Wainwright to swing the balance in the seventh.

Lester, who went 7-2/3 shutout innings in picking up the win in the series opener, went the same distance on Monday, yielding one run on four hits, striking out seven with no walks. Closer Koji Uehara came on to finish, registering a four-out save.

For Lester, the win silenced the suggestion by a Cardinals minor leaguer after Game One that the Boston left-hander had cheated by using a foreign substance in his glove, backed by a photo he captured off the TV screen.

Lester, who explained that he coated his glove with rosin before games to counteract his heavy sweating so he could get a better grip on the baseball, continued to excel on the World Series stage.

He improved to 2-0 in this series with a 0.59 earned run average, and in three career Fall Classic starts, Lester now boasts a 3-0 record, giving up just one earned run over 21 innings.

"Jonny (Lester) is just a stud, we really rely on him," said his battery mate Ross.

Lester returned the praise for Ross, who has been his catcher in recent starts.

"The biggest thing is me and Rossy have had a good rhythm," he said. "We just stuck to our pattern. Fortunately for us, Rossy hit that big double. It seems like it's a different guy every night that picks us up. That's the way it's been with us all year."

Boston struck first in the pivotal Game Five, taking a 1-0 lead on back-to-back doubles in the opening inning with Dustin Pedroia pulling a line-shot to left and red-hot David Ortiz rapping a sharp grounder over first base and into the right-field corner to score the run.

Ortiz finished the game 3-for-4, and is a remarkable 11-for-15 overall for the series. He was slow to gather himself after beating out a base hit in the eighth, but despite icing both his ankles after the game said he would be ready to go again in Game Six.

Adam Wainwright settled down after Boston's one-two punch in the first by retiring the next eight batters, the first five of those by strikeout.

The Cardinals tied the game in the fourth on a home run to straightaway center by Matt Holliday, the first run given up in a World Series game by Lester spanning 16 career innings. Carlos Beltran threatened to go back-to-back but his drive to left-center was caught just before the wall by Jonny Gomes.

It remained tied until the Boston breakout in the seventh. Wainwright was charged with all three runs after matching Lester's brilliance through six as he struck out 10 batters in his seven innings.

Lester gave way to Uehara with David Freese on second after a double down the right field line.

Uehara, who on Sunday became the first Japanese-born pitcher ever to register a World Series save, did it again on Monday. He struck out pinch-hitter Matt Adamsto end the eighth, and then retired the side in the ninth to send Boston home with a chance to end it on Wednesday.

St. Louis manager Mike Matheny said Boston used the same winning formula as before.

"He (Lester) threw the ball extremely well," Matheny said. "It came down to a big hit. They got the big hit when they needed it, and we couldn't put much together.

"He was the same pitcher that we saw last time. Couldn't get much going. He kept us down.

"You know, our guys have been backed up against the wall before, and this is something that isn't foreign to them. They know what we have to do. We just play our game. If we go about it the right way, we'll be right where we want to be."