BOSTON (AP) -- Jon Lester stood in the middle of Boston's quiet clubhouse and didn't try to sugarcoat the situation.
"It's hard for me to walk around this clubhouse and look guys in the eye right now," he said after giving up a career-worst 11 runs in the Red Sox's 15-7 loss to Toronto on Sunday that completed a three-game series sweep for the Blue Jays.
"I'm not pitching well. I'm not doing my job," he said. "Guys scored seven runs today. We should win this game. Like I said, it's embarrassing. That's all I can really say about it."
Brett Lawrie started Lester's day off to a poor note, hitting the game's first pitch for one of Toronto's four homers. J.P. Arencibia, Rajai Davis and Travis Snider also homered for the Blue Jays.
Toronto manager John Farrell was Boston's pitching coach from 2007-10 and offered his opinion on what's wrong with the left-hander.
"Through our scouting reports and seeing him earlier in the year, there's been a little more tendency to miss over the middle of the plate and up in the strike zone," Farrell said. "The devastating cutter that he's had for so long might not be as sharp right now and it gains a little length and our hitters are able to see it a little more on its flight to the plate. We laid off some tough
Lester (5-8) allowed a career-high four homers and nine hits. He was booed off the field after being pulled with no outs in the fifth.
Second baseman Dustin Pedroia said he spoke to Lester in the dugout between the first and second innings, hoping to improve his spirit.
"Basically just telling him that we have his back," Pedroia said. "Everyone goes through tough times. Just said, ‘However many starts you have the rest of the way, we're not going to win the World Series if Jonny's not himself, if I'm not myself.' He's not going anywhere. He's our horse."
Toronto (48-47) posted a season high for runs and climbed out of the AL East cellar, moving a half-game ahead of the Red Sox (48-48). The Blue Jays matched their season high with 18 hits.
Adrian Gonzalez hit a three-run homer and Jacoby Ellsbury a solo shot for the Red Sox, who play their next six games on the road against division leaders.
Boston opens a three-game series against AL West-leading Texas on Monday and has a three-game set versus the East-leading New York Yankees next weekend.
Henderson Alvarez (6-7) pitched 5 2-3 innings, giving up seven runs and seven hits.
Lawrie belted a 95 mph fastball completely out of Fenway Park over the Green Monster. Edwin Encarnacion and Davis sandwiched RBI doubles around Arencibia's run-scoring grounder, moving Toronto ahead 4-0. Jeff Mathis then put down a safety squeeze, scoring Davis to make it 5-0.
Gonzalez hit a three-run homer in the bottom half, but the Blue Jays scored four more runs off Lester on consecutive homers by Arencibia and Davis in the second.
Arencibia hit a three-run shot into the Monster seats after Lawrie walked leading off and Encarnacion drew a two-out walk. Five pitches later, Davis homered into the first row of seats above the left-field wall. After Lester fanned Snider for the final out, he walked slowly to the dugout to loud boos.
Mike Aviles' sacrifice fly made it 9-3 before Snider, the last batter Lester faced, hit a two-run shot onto a black tarp that covers two sections of center-field seats during day games to help the hitters' background. Lester's ERA ballooned to 5.46 from 4.80.
In the sixth, Boston made it 11-7 on back-to-back RBI hits by Aviles and Nick Punto. Toronto added four more runs in the eighth.
The Red Sox finished a seven-game homestand 3-4 after taking three of four from the Chicago White Sox.
NOTES: Farrell said RF Jose Bautista, placed on the 15-day disabled list Tuesday with a sore left wrist, is "coming along better than the medical staff could have envisioned." ... Boston 3B Will Middlebrooks and LF Carl Crawford were both rested. "He's been playing a lot since the hamstring," manager Bobby Valentine said of Middlebrooks, who missed seven games earlier this month with a tight left hamstring. "Day game after a night game might be testing it. I don't want to test it." Crawford had played in every game since coming off the DL for the first time Monday, following his recovery from left wrist and elbow injuries. ... It took nearly an hour to play the first two innings. ... The Blue Jays had the leadoff batter on in the first five innings -- all against Lester.