They're on the verge of another four-game skid fueled by a lack of offense as these division leaders play the first of four meetings Thursday night in Oakland.
The Athletics (51-33) scored seven times in dropping a season-high four in a row May 22-25, with the last five of those runs coming in a three-game sweep at Toronto.
Oakland finds itself in its worst offensive slump since then, as it pushed seven runs across the plate in dropping all three games in Detroit this week. The A's, who lead the AL with 425 runs, entered that series with nine wins in the previous 11 games.
''This wasn't a very good series for us - getting swept never feels too good," manager Bob Melvin said.
Brandon Moss went 4 for 4 with a homer and Coco Crisp also homered while going 3 for 4 in Wednesday's 9-3 loss. Moss is batting .423 over the last six games.
Toronto (47-39) was also having trouble scoring before sweeping a two-game series against visiting Milwaukee. The Blue Jays managed seven runs in losing three in a row before winning 4-1 on Tuesday and 7-4 on Wednesday.
Edwin Encarnacion's three-run homer with two outs in the ninth inning was the difference in the latest game. It was his 26th home run, and Jose Bautista and Juan Francisco also went deep for the Blue Jays, who lead the majors with 113 homers.
Encarnacion is batting .404 with six homers and 15 RBIs in the last 13 contests.
"For me, it's the best moment you have," Encarnacion told MLB's official website. "For any player, to have a walk-off home run ... everyone is happy on the team, and now we have a five-hour, happy flight to take (to Oakland)."
The A's will look to get back on track against R.A. Dickey (6-7, 4.24 ERA), who shut them down May 24. The right-hander had his best start of the season, allowing two runs and five hits over 8 1-3 innings of a 5-2 win.
Dickey, though, is trying to avoid losing four straight starts for the first time since May 13-28, 2004, while with Texas. He gave up four homers and five runs over six innings of a 5-4 defeat to the Chicago White Sox on Friday.
The home runs were the most he allowed since giving up six against the Tigers on April 6, 2006, in his first major league start as a knuckleballer. He's allowed 13 homers over his last eight starts after giving up three in his first nine.
''He's going to give them up,'' manager John Gibbons said. ''That's what that pitch does. You get a lot of fly balls on that pitch."
Dickey is 1-5 with a 4.83 ERA in seven road starts, but has a 2.25 ERA in four at Oakland while allowing two homers in 24 innings.
The A's will turn to Sonny Gray, who has struggled in the last month after getting off to a solid start. The right-hander is 2-2 with a 5.50 ERA in his last six outings after going 5-1 with a 1.99 ERA in his first 10.
Gray (7-3, 3.20) gave up a season high-tying five runs in a season-low five innings of Saturday's 7-6, 14-inning win at Miami.
He lost 5-4 in his only start against Toronto on Aug. 10, as Bautista went 3 for 3 with a two-run homer in their matchups. Colby Rasmus was the only other Blue Jay to get a hit off of him in six innings.