BOSTON — The Toronto Blue Jays limped into Boston for a weekend series having lost three straight games and slugger Jose Bautista to the disabled list in New York and were in the American League East cellar.

But by late Sunday afternoon, the Jays had scored 28 runs and swept three games from the Red Sox, bombing the floundering Jon Lester for a career-worst 11 runs in four-plus innings (nine in the first two inning) in a 15-7 victory that dropped Boston into last place in the division.

“A very good weekend considering what we came out of in New York and the loss of Jose,” Jays manager John Farrell said after his team pounded out a season high in runs and equaled its season best with 18 hits.

“We got it handed to us in New York, but this weekend we showed a lot of character coming in here. The guys bounced back and we had a very good weekend here. This is not an easy place to play.”

The Jays, who had to put Bautista on the disabled list in New York with a wrist injury, had gone 6-11 in their previous 17 games at Fenway before the weekend.

J.P. Arencibia drove in four runs with a three-run homer and a groundout, Rajai Davis had a loud solo homer and three hits (two RBIs), Brett Lawrie hit the first pitch of the game for a homer, and Travis Snider, recalled when Bautista went down, hit his first big-league homer of the year and drove in three runs for the Jays.

“Travis coming up has injected us with some life,” said Farrell. “You're never going to replace a bat like Jose, but we've got multiple ways to score some runs and we've still got power in the middle of the order.”

Said Snider: “We've struggled here before ... to come out with a sweep is really something to build on.”

The win gave the Jays a 48-47 record, a half-game ahead of the Red Sox and a half-game behind Tampa Bay. All of that means, of course, that Toronto is still in the wild card picture.

Henderson Alvarez struggled through 5 2/3 innings and raised his record to 6-7. He gave up a three-run homer to Adrian Gonzalez (No. 9) in the first inning and a solo shot to Jacoby Ellsbury (No. 1) in the fifth. Mike Aviles drove in two runs for the Sox.

Over his last three starts, Lester, who again heard the boos Sunday, has gone 0-3, yielding 25 hits, 21 earned runs and 10 walks in 12 1/3 innings, his ERA going from 4.33 to 5.46. The Blue Jays, who had reached him for nine runs in his previous career-worst start on Aug. 20, 2010, went 9-for-18 against him.

Lester and Josh Beckett, the 1-2 pitchers in the Sox rotation, are both 5-8, with a combined 5.03 ERA. The team is 13-23 in their 36 starts.

Farrell, Lester's pitching coach in Boston, noticed the lefty's cut fastball is catching too much of the plate. He said his hitters “laid off some tough pitches.”

Asked if his confidence is shaken, Lester said, “It's obviously not at the highest it's ever been, but ... the thing is nobody's going to feel sorry for me. I gotta go out and pitch.

“I gotta pitch better so I'm not worried about my confidence, I'm not worried about my mechanics, I'm not worried about anything but trying to execute pitches. And I'm not doing that, so I'm trying to get back to trying to keep it simple.”

As far as what has gone wrong, he said, “Name it. Everything.”

It took one pitch for Toronto to take a 1-0 lead, 10 pitches to make it 2-0, 16 for 3-0, 19 for 4-0, 27 for 5-0 and, after the Gonzalez homer, it became 8-3 on the 45th pitch and 9-3 on the 51st.

Lawrie started a five-run first inning with his ninth homer of the year, and Arencibia (No. 15, second in as many games, this one a three-run shot) and Davis (No. 5) gave Toronto its fifth back-to-back homers of the season to make it 9-3 in the second.

NOTES: Boston pitchers have allowed a major-league-worst 83 first-inning runs and have a 7.03 first-inning ERA. The Sox have allowed first-inning runs in 12 of the last 14 games, 17 of the last 21. ... Lester is the first Red Sox pitcher to allow 11 runs in a game since Doug Bird on May 5, 1983. ... Bautista is coming along better than expected but no word on whether he can rejoin the team when he becomes eligible Aug. 1. Righty Brandon Morrow (oblique) has made progress since a setback, the hope being he can return in mid-to-late August. ... Boston's Carl Crawford, 2-for-12 in the last three games after going 5-for-10 in his first three games of the season earlier in the week, was rested, according to plan, while third baseman Will Middlebrooks, 12-for-63 since Kevin Youkilis was traded June 24 and bothered by a hamstring, also sat. ... Red Sox reliever Andrew Bailey, who has yet to pitch for the team after thumb surgery, is about a week from a minor league rehab assignment, while fellow reliever Scott Atchison, on the 15-day DL with right forearm tightness, is slated to make a rehab appearance Friday and should return shortly thereafter. ... The Red Sox open a tough six-game road trip in Texas Monday night, then move on to New York for three with the Yankees. Roy Oswalt, the scheduled Texas started Monday night, was scratched with a lower back issue, with Scott Feldman taking his spot. ... The Blue Jays go home and open a three-game series with sizzling Oakland Tuesday night. ... Farrell improved to 129-128 in his two seasons.