04/06/2013 03:54 EDT | Updated 06/06/2013 05:12 EDT

J.P. Arencibia, Colby Rasmus both homer as Blue Jays down Red Sox 5-0

TORONTO - Blue Jays catcher J.P. Arencibia enjoys belting homers, but not as much as calling a two-hit shutout.

Arencibia and Colby Rasmus both homered, four Toronto pitchers combined on a two-hit shutout while striking out 11 and the Jays defeated the Boston Red Sox 5-0 on Saturday afternoon.

"My most exciting part of the game is guys going out there and pitching out of jams and keeping them at a zero," Arencibia said. "My job is to try and do the best to keep that zero on the scoreboard regardless of the hits or whatever they get.

"The zeros are the important part and we were able to do it."

Arencibia and Rasmus provided the offensive fireworks for Toronto (2-3), delighting a vocal Rogers Centre gathering of 45,797 for a Jays squad that was minus slugger Jose Bautista (ankle) for a second straight game.

Boston (3-2) won the series opener 6-4 on Friday night but received a huge scare when right-hander John Lackey (0-1) came off the mound in the fifth clutching his right arm following an inside pitch to Toronto's Jose Reyes.

Lackey was making his first major league appearance since Tommy John surgery in 2011 on his right elbow and his obvious discomfort brought Red Sox manager John Farrell and the club's medical staff running in from the dugout.

Lackey left with what was later diagnosed as a right biceps strain, although the severity wasn't immediately clear. He allowed five hits and two runs (both earned) and a walk while striking out eight before giving way to right-hander Alfredo Aceves.

"It felt like a pretty good cramp, it's all in the biceps, it wasn't the elbow," Lackey said. "A little scary when it happened, for sure.

"My hand didn't go numb or anything like I've had with the elbow stuff. I felt really good. I made one mistake. I was pounding the strike zone pretty well, had some strikeouts. The tests they ran on me here looked pretty good. Hopefully it's nothing too crazy."

Red Sox manager John Farrell said Lackey will fly back to Boston on Sunday to undergo an MRI.

"(The) elbow is fine, this is the belly of the belly of the biceps," Farrell said. "It's kind of an abnormal area for a guy to feel that grabbing sensation on one pitch ... the encouraging thing is as he came out of the game the soreness and the cramping feeling had subsided."

Up to that point, Farrell liked what he saw from Lackey.

"He looked sharp," Farrell said. "He had good action to his secondary stuff, the velocity was probably the best we've seen to date.

"He was free and easy, he threw all of his pitches for strikes."

Meanwhile, Toronto starter J.A. Happ (1-0) was outstanding, allowing just one hit over 5 1-3 innings with a wild pitch. He walked three and struck out six before giving way to fellow right-hander Steve Delabar with one on and one out in the sixth.

Aaron Loup and Sergio Santos worked the final two innings for the Blue Jays.

"He was throwing strikes, he was mixing it up with his changeup," Arencibia said of Happ. "He had a really good changeup, a good slider, a good breaking ball.

"I really think he commanded his secondary stuff well, which made his fastball that much better."

Happ said an effective changeup was key to his success.

"I think that's going to be a big pitch for me," he said. "I had a couple good ones today to keep them off balance, I think it makes the fastball that much better.

"I used to use it quite a bit and I'm trying to get back to the point where I find that comfort zone with it. It can be a feel pitch so when it's not there it makes it tough. It was working for me pretty good."

Toronto manager John Gibbons certainly noticed.

"Happ was dynamite," Gibbons said. "The thing that was really big for him was he started throwing his changeup a little more, it was a big pitch for him.

"You can kind of classify him as a power lefty ... he's got that fastball he can throw by you up in the zone, that's kind of his trademark. But that changeup makes that fastball even better and complements his breaking ball as well."

After surrendering a game-opening double to Jacoby Ellsbury, Happ retired seven straight batters before Pedro Ciriaco walked in the top of the third. He landed at third on a wild pitch and Arencibia's throwing error and tried scoring on Ellsbury's fielder's choice but was thrown out at the plate by Jays first baseman Edwin Encarnacion. Ellsbury stole second and Shane Victorino walked, but Happ got Dustin Pedroia to pop up and end the threat.

After allowing Reyes's single to open the first, Lackey retired eight straight before Reyes — who was a triple short of hitting for the cycle Friday night — and Rajai Davis registered consecutive two-out singles before Lackey fanned Melky Cabrera to end the inning.

Arencibia opened the scoring with a two-run homer in the fourth, his third of the season. The one-out blast to deep centre field also brought home Adam Lind, who had singled.

Rasmus then took Aceves deep in the sixth with a three-run shot, his second of the season, after both Lind and Mark DeRosa walked.

Pedroia delivered Boston's second hit of the game — a two-out single off Santos in the ninth — before Rasmus showed great range tracking down Mike Napoli's long fly ball at the fence to register the final out.

Notes: Lind's single was his first hit in 15 at-bats this season. ... Not surprising, Farrell was again roundly booed when introduced as Boston's manager prior to the game. ... Toronto selected the contract of right-hander David Bush from triple-A Buffalo before the game and designated right-hander Jeremy Jeffress for assignment. Bush, 33, returns to Toronto after spending 2002-2005 with the Jays organization. ... Toronto knuckleballer R.A. Dickey is slated to make his second start of the season Sunday while Boston counters with left-hander Jon Lester. ... Toronto is off Monday before opening a three-game series in Detroit on Tuesday.