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The Blue Jays traded for J.A. Happ last week hoping he could solidify their injury-riddled rotation.

To do that, Happ will have to pitch better than he did Tuesday night.

Yoenis Cespedes hit a three-run single off Happ and the Oakland Athletics beat the Toronto Blue Jays 7-2 for their season-best sixth win in a row.

Acquired from Houston along with two other pitchers in a 10-player deal last Friday, Happ is pitching out of Toronto's bullpen for now. Manager John Farrell and general manager Alex Anthopoulos have said they'll be monitoring each member of their rotation, and will consider sliding Happ in to replace any struggling starter.

Against Oakland, however, it was shaky relief work from Happ and Chad Beck that allowed the A's to break open a close game with a five-run seventh inning.

"We were in this game, we were battling and I took us right out of it so it's not a good feeling," Happ said.

Travis Snider and J.P. Arencibia each hit solo homers and Brett Lawrie had three hits for the Blue Jays, whose three-game winning streak came to an end.

All seven Oakland runs were scored with two outs.

"In two innings, the third out was obviously a little elusive," Farrell said.

Derek Norris hit a two-run homer and Travis Blackley won his third straight decision as the A's improved to 15-2 in July. Oakland (52-44) is eight games over .500 for the first time since July 12, 2008.

"We're on a roll," Blackley said. "We're enjoying the game and we expect to be able to come up big in certain situations and we're doing it over and over again."

Blackley (3-2) allowed one run and five hits in seven innings. The left-hander, who has not lost since June 10 at Arizona, walked one and struck out a career-best eight.

"I felt a bit like a fish out of water early, just didn't have a rhythm," Blackley said. "The cutter was disgustingly bad today, it didn't work at all. Luckily the curveball was just phenomenal today. I was able to throw it for strikes and below the zone for swings. That pretty much changed the game for me today because I really didn't hit many spots with any other pitch."

Evan Scribner worked the eighth and Jim Miller gave up Arencibia's 16th homer in the ninth.

Brett Cecil (2-3) allowed two runs and five hits in six innings and has won just once in his past six starts.

"Brett used his changeup, his curveball and his cutter in to right-handers and had a number of batters off-balance," Farrell said.

Cecil has allowed at least one home run in all seven of his starts this season, and 15 of his past 18 overall.

Once Cecil departed, the Athletics put the game away with a five-run outburst in the seventh. Brandon Hicks doubled and Weeks chased Beck with an RBI triple. Happ came on immediately gave up an RBI double to Coco Crisp, then walked Jonny Gomes.

Farrell acknowledged bringing Happ into "a tough spot," but figured the matchup favored his new lefty, who had pitched 2-3 of an inning at Boston in Saturday's 7-3 win, his Blue Jays debut.

"The fact is Crisp was a .200 hitter against left-handers and I thought that was the move, to turn him around to the right side, and he hits the first pitch inside the bag for a double," Farrell said.

After a double steal, Josh Reddick walked to load the bases for Cespedes, who had struck out swinging three times. On Happ's 3-2 pitch, Cespedes snapped an 0 for 8 slump by lining a bases-clearing single to center.

Cespedes has at least one hit in 10 of his past 11 games and has 16 RBIs in that span. He's batting .487 (19 for 39) in 10 games since the All-Star break.

"He's a tough kid, he doesn't get down on himself," Athletics manager Bob Melvin said of Cespedes. "I've often said that. He'll get upset with himself and you can see he kind of wears it on his sleeve sometimes but he goes up there with more conviction the next time."

Oakland opened the scoring in the second when Brandon Inge reached on a two-out single and Norris hit Cecil's next pitch into the second deck in left, his third homer of the season.

The Blue Jays answered in the third on a leadoff homer by Snider, his second. Snider also connected in Sunday's 15-7 victory at Boston.

NOTES: Oakland has won seven of its past 11 meetings with Toronto, dating to 2011. ... Blue Jays OF Jose Bautista (left wrist) is "making good strides" in his return from the injury, Farrell said, and could be swinging a bat and hitting off the tee soon. ... Toronto RHP Sergio Santos underwent season-ending shoulder surgery Tuesday. ... An MRI on Blue Jays RHP Jason Frasor (forearm) showed no tear, but he has been told not to throw for two weeks. ... Oakland LHP Dallas Braden (shoulder) threw a 33-pitch bullpen session Tuesday and could face batters when he throws next. ... Athletics RHP Brandon McCarthy (shoulder) will throw a 45-pitch simulated game at Oakland's spring training facility in Arizona on Wednesday. ... A's LHP Brett Anderson (elbow) will pitch four innings at Triple-A Sacramento on Thursday. ... Reddick threw out Lawrie trying to advance to third in the first, his 10th outfield assist.