The victory increased Toronto's lead over the second-place New York Yankees to 5 1/2 games. The third-place Orioles dropped to six games off the pace.
The Blue Jays' magic number to eliminate both the Yankees and Orioles is five. The Orioles and Blue Jays both have 10 games to play, one more than the Yankees, who open a three-game series here tonight.
Roberto Alomar, John Olerud and Pat Borders homered for the Blue Jays, who won for the 10th time in their past 11 games. Alomar also contributed a two-run triple to back up another strong pitching performance by veteran right-hander Dave Stewart.
Stewart (11-8) didn't give up a hit through the first four innings and allowed only three, two by Scott Cooper, before leaving after the seventh inning. It was the third win in a row for Stewart, who hasn't lost since dropping back-to-back decisions to Seattle on Aug. 21 and 26. It was also the third straight time he has allowed only one run.
"It seems like I've been fighting off injuries most of the year," said Stewart, who opened the season on the disabled list and has pitched through some nagging aches.
"But right now I'm throwing the ball real good. I had real good command of my hard stuff tonight [last night], and I used a lot of off-speed stuff early just to let them know I would do it.
"Then, as we got deeper into the game, I switched back to hard stuff. If I can go out there healthy, I can get the job done."
Nate Michey (1-1) gave up four runs in the first three innings and was charged with his first loss in the major leagues. The rookie right-hander was charged with all five runs scored by the Blue Jays, although he allowed only five hits in the 6 1/3 innings he worked.
However, what the Blue Jays' offense lacked in quantity, it made up for in distance. Alomar (17) and Olerud (24) homered in the first two innings and Alomar's two-run triple in the third made it 4-0.
Cooper got the first hit for the Red Sox in the fifth, a single to right, and his seventh-inning double set up the only Boston run, produced on a pair of infield outs.
Borders finished the scoring in the home half of the seventh, hitting his eighth home run of the year into the second deck in left field.
For the Blue Jays, who have been hurt by inconsistent pitching all year, the performance of Stewart was particularly encouraging.
l Stewart's physical condition will be of vital importance during postseason play. With Jack Morris sidelined for the year, he is the most seasoned starter on the staff, one that manager Cito Gaston won't hesitate to use in critical situations.