Derek Norris and Jed Lowrie each had two hits for the A's, who acquired third baseman Alberto Callaspo from the Angels for infielder Grant Green in a trade announced during the game. Callaspo was hitting .253 with five home runs and 36 RBIs entering Tuesday.
Buehrle (7-7) extended his scoreless innings streak to 20, did not walk a batter and struck out two. He retired 10 of the first 11 batters he faced five days after tossing a two-hit shutout against the Houston Astros.
"He does everything right," Gibbons said. "He's 'old reliable.' He's been around for a while and has had a tremendous career."
Buehrle thought he had given up a home run to Coco Crisp, the game's first batter. He also thought Josh Reddick got him in the third. Both balls died on the warning track.
"You still have to make your pitches and hit location and it is still a lot of luck," said Buehrle, who has won at least 10 games in each of the past 12 years. "This is a tough place to hit at night."
A's manager Bob Melvin was impressed with Buehrle's craftiness.
"We just couldn't get anything going against Buehrle," Melvin said. "Even though he doesn't throw hard, he bullies the right-handers in with cutters and throws changeups, back-door breaking balls, and keeps you off balance."
Dan Straily (6-5) lost his third straight decision, giving up five runs -- two earned -- on six hits. He walked two and struck out two.
"You saw some two-strike hits, which means he probably wasn't as precise as he needs to be, especially when he's ahead," Melvin said. "Then he got some balls in the middle of the plate."
Blue Jays right-hander Steve Delabar struck out the side in the eighth on nine pitches and leads all AL relievers with 70 strikeouts.
"You can't get any more dominating than that," Gibbons said. "You don't see that too often."
Bautista's two-out home run in the first put Toronto on the board.
The Blue Jays added an unearned run in the fourth. Encarnacion, Adam Lind and Rasmus hit consecutive singles, with Yeonis Cespedes misplaying the ball in left field, allowing Encarnacion to score.
The Blue Jays improved to 11-21 since their major league-best 11-game winning streak.
Darren Oliver pitched the ninth and went over the 1,900-inning mark for his career.
"He's had a marvelous career that speaks for itself," Gibbons said. "He's a lot like Buehrle. They both keep answering the bell."
A's INF Eric Sogard was credited with a single in the first inning of Monday night's game, with the error taken away from Edwin Encarnacion. It gives Sogard an eight-game hitting streak. ... A's LHP Brett Anderson (foot) threw 57 pitches in a side session. He'll likely throw live batting practice on Friday. ... RHP Bartolo Colon (14-3, 2.54 ERA) is scheduled to start for the A's on Wednesday. He's 10-5 lifetime against the Blue Jays. ... Blue Jays RHP R.A. Dickey (8-11, 4.86) makes the start for the Blue Jays. He's 0-3 in his past four starts after a season-best three-game winning streak. ... Encarnacion has reached base safely in 16 of his past 25 plate appearances. ... Buehrle last pitched against the A's in 2011 and has a three-game winning streak against them.
17,479 (49.8% full) - % is based on regular season capacity
58 degrees, clear
Home Plate - Alfonso Marquez, First Base - Ted Barrett, Second Base - Mike DiMuro, Third Base - Scott Barry
Jose Bautista hit his 25th HR of the season Tuesday, his 4th straight season with at least 25 HR. He's the 4th player in Blue Jays franchise history to accomplish the feat, joining Carlos Delgado (9), Joe Carter (6) and George Bell.