BOSTON -- The Toronto Blue Jays have not hit home runs this year with quite the stunning regularity that they did the previous two seasons.

On Monday night, they turned back the clock.

The Blue Jays belted four homers, including three off of reigning American League Cy Young Award winner Rick Porcello, to cruise to a 10-4 win over the Boston Red Sox.

Less than a week after Porcello held the Blue Jays to one run over 6 1/3 innings to earn a win at Rogers Centre, Kendrys Morales, Jose Bautista and Raffy Lopez all took him deep Monday, knocking him out of the game in the sixth with Toronto up 7-2.

"We've been swinging the bats well," acting Blue Jays manager DeMarlo Hale said. "You can really see guys grinding, and any time you see innings where you score three runs, you're doing some damage."

The Red Sox (77-61) saw their AL East lead slip to 2 1/2 games over the New York Yankees, winners over the Baltimore Orioles earlier in the day. Toronto improved its AL East-worst record to 64-74.

Blue Jays starter J.A. Happ (7-10) went 5 2/3 innings, allowing three runs (one earned) on six hits with three strikeouts and three walks.

Porcello (9-16) allowed seven runs on 10 hits with three strikeouts and one walk over 5 1/3 innings.

"They got six of seven runs off him with three swings," Red Sox manager John Farrell said. "It all comes down to location."

Steve Pearce led off the game with a double and Justin Smoak walked, giving Morales a chance to jump-start the Blue Jays with a two-out, three-run home run to right field. The homer snapped Morales' 0-for-14 skid.

Eduardo Nunez got the Red Sox on the board in the bottom of the second, poking a two-out single down the right field line to score Chris Young and Christian Vazquez and cut the Toronto lead to one.

The Boston offense went quiet for a long stretch after that, collecting two hits and no runs over the next three innings.

"Throughout the course of the year, we've created opportunities, and the runs have been there," Farrell said. "Two-out base hits are key for us. There were multiple opportunities tonight. Leadoff double, can't cash it in. The opportunities are there, but we haven't cashed them in."

Bautista took Porcello deep to center field in the top of the third, making it 4-2 Toronto. It was Bautista's fifth career home run off of Porcello, his 25th at Fenway Park and his franchise-best 42nd against the Red Sox -- also the most of any active player against Boston.

The Blue Jays forced Porcello out of the game in the sixth, with Ryan Goins singling, Darwin Barney bringing him home on a double to left field and Lopez hitting his third home run of the season.

"I thought (Porcello) was settling in after the Bautista home run," Farrell said. "It was a two-run ballgame, we're chipping away, thought he settled in in the fourth and fifth, gets the leadoff out in the sixth, thought, 'OK, he's got a chance to get through the order three times,' but the bottom of the order did some damage against him."

Lopez's two-run shot cleared the bullpen and went five rows deep into the right field stands to make it 7-2.

"It was pretty awesome," Lopez said. "My freshman year, I went to school in Boston. To come back here and do that was a lot of fun. I got a lot of text messages and stuff like that from friends back at home."

Christian Vazquez, Deven Marrero and Nunez hit back-to-back-to-back singles in the sixth, with Nunez's poke into right field bringing Vazquez across for Boston's third run. An inning later, Andrew Benintendi led off with a walk, moved to second on a wild pitch and scored when pinch hitter Mitch Moreland's grounder took Barney deep into his position at second base, cutting the Blue Jays' lead to 7-4.

Mookie Betts had an opportunity to make things interesting in the eighth when he came up with two outs and Brock Holt on second via a ground-rule double. Betts battled Ryan Tepera to a full count, but Tepera induced a fly ball to right field to end the threat.

Justin Smoak got in on the long-ball fun in the ninth, crushing a 2-2 delivery from Matt Barnes to center field and making it 8-4. Morales followed Bautista's double with one of his own to score him, and Kevin Pillar brought Morales home with a single for the Blue Jays' 10th run.

"This park, you never seem to have enough runs," said Hale, who spent six years as a coach with the Red Sox. "Anytime you can tack on, it helps."

Tim Mayza retired the side in order in the ninth to close out the win and bring Toronto's record at Fenway Park to 2-2 this year.

NOTES: Red Sox SS Xander Bogaerts returned to the lineup Monday, after sitting three straight games in the midst of a 39-for-198 (.197) slump over the last 53 games. He went 0-for-4. Eduardo Nunez, who played shortstop during Bogaerts' respite, moved to third base. ... Blue Jays manager John Gibbons missed his third straight game, tending to a personal matter. Bench coach DeMarlo Hale acted as Toronto's manager. ... The Red Sox sat three regular starters for Monday's series opener against Toronto. Dustin Pedroia sat in favor of rookie Deven Marrero. Chris Young started in left field, replacing Jackie Bradley Jr., and Sam Travis took first base over for 1B Mitch Moreland.