Lester (18-8) allowed four hits over seven innings to win his fifth straight start and become the first Red Sox lefty to win 18 games since Bruce Hurst in 1988. Victor Martinez hit a solo homer for Boston, and J.D. Drew had a two-run shot in a five-run fifth.

The Blue Jays were mathematically eliminated from the playoff race with the loss.

"It's always disappointing when the playoffs are starting and you're not one of the teams in it," second baseman John McDonald said. "We set out goals of making the playoffs and the World Series."

Bautista had homered in three straight games, giving him a franchise-record 49 for the season and a lead of 10 in the majors over next-best Albert Pujols of the St. Louis Cardinals.

But Bautista, who grounded out to third with nobody on in the first inning, was out on a fielder's choice to the shortstop with the bases loaded in the third and another to the third baseman with the bases loaded in the fifth.

"Normally Bautista would respond in that situation," Blue Jays manager Cito Gaston said. "He threw him a couple of good pitches. We knew he was tough, and he was today."

Lester struck out only four to snap a streak of four straight games in which he'd fanned at least 10. He said he tried to keep Bautista off-balance in the seven-pitch at-bat in the first inning, mixing in curveballs and changeups and working both sides of the plate.

"I think that set up his later at-bats," Lester said. "Obviously, his stats speak for themselves. He's obviously a dangerous threat that you don't want coming up two times with the bases loaded."

Shaun Marcum, who hadn't allowed more than three runs in an outing in six starts, lasted 5 1/3 innings for Toronto and gave up six runs on nine hits while striking out three. It was his worst start since he allowed eight runs, including a career-high four homers, to the Red Sox on Aug. 11.

Marcum, who previously pitched last Sunday, said he fell out of a groove.

"You get in a routine. It sets the whole routine back a little bit," he said. "I don't think it's rust. You get on a good roll and it throws you off."

Marcum (12-8) gave up Martinez's solo homer in the fourth, then got into real trouble in the fifth when Jed Lowrie and Bill Hall singled to start the inning and Daniel Nava followed with a ground-rule double over the short fence down the right-field line. Yamaico Navarro singled to left to score Hall, and Nava came in when left fielder Mike McCoy let the ball roll past him for an error.

One out later, Drew hit a two-run homer over the Red Sox bullpen to make it 6-0.

Game notes
The last AL pitcher to strike out at least 10 batters in five straight games was Johan Santana, with five in a row for Minnesota in 2004. Pedro Martinez was the last Red Sox pitcher to do it, whiffing at least 10 batters in five consecutive games in 2001. ... The Red Sox made a game-time decision to rest third baseman Adrian Beltre, who rolled over his left wrist diving for a grounder on Saturday. ... Toronto sat second baseman Aaron Hill for a second straight game. He left Friday's game after being hit by a pitch on his right wrist.