Cecil Fielder, George Bell and Garth Iorg hit home runs in Toronto to help beat Detroit.
The Blue Jays remained 1 1/2 games ahead of New York in the American League East. The Yankees won in Milwaukee, 9-4, in 10 innings. Toronto will start a four-game series in New York Thursday night.
Winner Jimmy Key (12-6) took a 5-1 lead into the ninth. But Lance Parrish singled with one out and Chet Lemon followed with his 14th home run of the season. Tom Henke relieved Key and got the final two outs for his 10th save. Mickey Mahler took the loss, going 7 1/3 innings in his first AL start.
Fielder broke a 1-1 tie in the second inning with his third homer.
Bell and Iorg homered in the eighth. Bell broke a zero-for-16 slump with his 28th homer, a bases-empty shot off Mahler. Iorg hit a two-run homer, his fifth, off reliever Bill Scherrer.
Parrish led off the Detroit second with his 28th homer, tying the score, 1-1. One out later, Larry Herndon tripled and Darrell Evans followed with a fly ball that right fielder Jesse Barfield caught and threw home in time to nail Herndon.
"It was key factor, no doubt," Barfield said of his 17th assist of the season, second in the league to Kirby Puckett's 19. "It was a rally killer.