Toronto left-hander J.A. Happ (2-1) struck out nine in six innings. Happ gave up one run, five hits and three walks.

Pearce has homered in each of the past three games. His third-inning shot on Monday came on a 3-0 pitch from Orioles right-hander Dylan Bundy (0-1).

Donaldson added insurance with his fourth career grand slam to cap a five-run ninth as Toronto blew open a close contest.

Manny Machado homered for Baltimore's lone run. Trey Mancini went 3-for-4 with a walk and Machado reached base three times on two hits and a walk, but the Orioles were 0-for-12 with runners in scoring position.

Bundy struck out 10 in seven innings, marking the fourth time he has fanned 10 or more in his career. He allowed two runs, four hits and issued two walks.

The announced attendance was 7,915 on a cold night in which it was 44 degrees at first pitch.

Curtis Granderson walked to open the third before Bundy struck out Donaldson and Justin Smoak.

Bundy fell behind with three straight balls to Pearce, who had the green light and jumped on the next offering. The blast landed well beyond the fence in left-center field to give the Blue Jays a 2-0 lead.

Happ worked out of jams the first two innings while recording all six outs by whiffing hitters.

But Machado drilled a 2-2 pitch over the wall in left-center field in the third to get Baltimore on the board.

The Orioles loaded the bases with one out in the fifth but came up empty when Adam Jones hit into an odd double play to end the inning. Jones hit a comebacker to Happ, who threw home for the second out, but the toss to first from Blue Jays catcher Russell Martin hit off Jones' back and two runs came around to score.

But home plate umpire Chris Segal called Jones out for running inside the baseline, negating the runs and maintaining Toronto's 2-1 lead.

Granderson drew a bases-loaded walk in the ninth to give the Blue Jays a 3-1 lead. Donaldson followed with his 423-foot shot to center off left-hander Nestor Cortes Jr.

Toronto's Kendrys Morales departed in the second inning for a pinch runner due to left hamstring tightness.

--Field Level Media