OAKLAND, Calif. -- The Oakland Athletics trailed by a run when they came to the plate in the bottom of the fifth inning against the Boston Red Sox on Saturday afternoon at Oakland Coliseum.

That's when the A's turned the game into their personal Home Run Derby.

Mark Canha, Khris Davis and Chad Pinder each hit a monster home run in a five-run fifth inning, and Jed Lowrie went deep in the sixth to power the A's to an 8-3 victory.

The A's defeated Boston for the third straight time in the four-game series. They will go for the sweep on Sunday afternoon.

"Day games, the ball carries a little more, but I don't know if any of them would have been affected," Oakland manager Bob Melvin said. "It seems like they got longer and longer. Canha crushed that ball. K.D., we've seen it, and the Pinder one, I don't even know how to explain that.

"He's getting more and more comfortable at the big-league level. He has power. We've talked about him as a hitter. He's really starting to get comfortable, so good for him."

Canha launched a leadoff home run into the left-field seats off reliever Ben Taylor (0-1) for his third blast of the season and second in two games. His shot traveled an estimated 453 feet. Canha hit a walkoff homer leading off the 10th inning Friday night in the A's 3-2 win over the Red Sox.

Lowrie, who went 3-for-5, followed with a single and Davis crushed a two-run homer to left-center field, his team-high 13th of the season, that went 429 feet.

Canha and Davis each hit belt-high fastballs from Taylor, who exited after walking Trevor Plouffe.

Then with one out, Pinder launched Noe Ramirez's first pitch 460 feet into the second deck in left-center field for a two-run shot, his fourth home run of the season, making it 7-3.

"It's one of those swings where you kind of just black out," Pinder said. "You see it and you hit it, and you don't know what happens after. I sold out on the fastball in. I was like, see something up, an elevated fastball, and just try to get your hands in, get the bat head out there, and luckily enough I got the pitch I was looking for and put a good swing on it."

According to the A's, Pinder is believed to be the fourth player to reach the Plaza Reserve section since the so-called Mt. Davis addition was built for the Oakland Raiders in 1996. Pinder joined former Athletics slugger Mark McGwire (May 7, 1996), ex-Colorado Rockies player Larry Walker (July 19, 1999) and San Francisco's Jarrett Parker (Sept. 25, 2015).

"That was amazing," Davis said. "He's got a great swing."

Lowrie hit a solo shot to right off Ramirez in the sixth inning, extending Oakland's lead to 8-3.

The A's entered the game with 59 home runs, tied for second in the American League, one behind the New York Yankees.

Hanley Ramirez hit a solo home run and had two hits for the Red Sox, who have lost three straight games for the first time this season.

"There's tough times throughout the year, and obviously in the market we play in, it's magnified, so you know right now we haven't played very well," Red Sox second baseman Dustin Pedroia said. "So take your beating like a man and show up tomorrow and try to hand one out.

"We're playing hard. We just haven't made our breaks, but the good teams do."

A's left-hander Sean Manaea (2-3) allowed three runs (two earned) and five hits in five innings. He struck out three and walked none. In his first career start against Boston last year at Fenway Park, he allowed eight runs and 10 hits in 2 2/3 innings of a 13-5 loss.

Frankie Montas threw three shutout innings of relief, striking out five, and Josh Smith pitched a scoreless ninth for the A's. Oakland relievers have pitched 25 consecutive scoreless innings at home.

Red Sox left-hander Drew Pomeranz, a former Athletics pitcher, allowed two runs (one earned) and five hits but lasted only four innings in his first career appearance against Oakland. Pomeranz threw 97 pitches -- 56 of them in the first two innings -- struck out six and walked one in a no-decision.

During the top of the fifth, Pomeranz had what appeared to be a heated discussion with Red Sox manager John Farrell in the dugout.

"He didn't want to come out of the game," Farrell said. "So that was the discussion we had, and it's been settled."

NOTES: Red Sox LHP David Price (strained left elbow) will make a second rehab start for Triple-A Pawtucket on Wednesday. ... A's manager Bob Melvin was ejected for the first time this season when he was tossed in the bottom of the second by third base umpire Mike Winters. ... A's RHP John Axford (strained right shoulder) was activated from the disabled list, and RHP Ryan Dull (strained right knee) was placed on the 10-day DL. An MRI showed no structural damage for Dull. Axford had been on the disabled list since April 2. Dull was injured in the 10th inning Friday night against Boston while making a pitch. ... Red Sox 1B Mitch Moreland was out of the lineup, and Red Sox manager John Farrell said he hopes to give 2B Dustin Pedroia a day off Sunday. ... After an off day Monday, the Red Sox will have RHP Rick Porcello start Tuesday and LHP Chris Sale on Wednesday against Texas at Fenway Park.