TORONTO -- Adam Ottavino pumped two fastballs for strikes past Vladimir Guerrero Jr.. Ahead in the count, he decided to stick with what was working. The reliever reached back for more heat, and when it yielded a softly-hit grounder with no fielders in its path, he immediately pinned his hands to his cap.

Guerrero’s two-run triple rattled into foul territory down the right-field line, allowing Bo Bichette and Cavan Biggio to race home with the tying and deciding runs as the vaunted Yankees bullpen stumbled in the Blue Jays' 5-4 victory on Saturday afternoon at Rogers Centre.

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"It happened really quick," Ottavino said. "By the time I looked up, I saw that the ball was over in that area. I looked over and saw [first-base umpire Manny Gonzalez] call it fair. I was kind of in a little bit of disbelief."

Guerrero’s big hit was set up by a walk and a single, one half-inning after the Yankees claimed the lead on DJ LeMahieu's sacrifice fly.

Ottavino worked the count to 2-2 on Bichette but couldn't put the rookie away. Bichette fouled off a couple of sliders and looked at a cutter outside to run the count full. Bichette fouled off another slider before Ottavino's ninth pitch of the showdown sailed outside for the free pass.

"I think the mistake was the walk," Ottavino said. "A good battle there. I would have liked to do a little better job making him earn his way on base, Bichette. No excuse; got to get it done and I didn't today."

Biggio cracked his bat on the first pitch for a hit to right field, preceding Guerrero's triple.

"The walk to Bichette obviously hurts him, then the Biggio base hit," manager Aaron Boone said. "You get Guerrero down there and it's just one of those defensive [swings] where the ball finds a hole. That was the difference in the game, but I thought overall he threw the ball fine."

Gary Sanchez homered in his return from the injured list and red-hot Gio Urshela rounded the bases for his sixth homer in five games, though it was not enough to prevent the Yanks from taking their first loss while utilizing an opener this year.

"I felt good at the plate today," Sanchez said through a translator. "I was able to put a good swing on the ball. It felt good."

New York fell to 11-1 in “opener” games, having tabbed Chad Green to work a scoreless first inning.

After Sanchez's 25th homer of the year -- and first since the All-Star break -- landed in the left-field seats, Teoscar Hernández greeted Chance Adams with a three-run homer in the fourth, with two of those runs charged to Stephen Tarpley.

Urshela's 17th blast of the season cleared the wall in the sixth off Tim Mayza, tying the game, and New York grabbed the lead in the seventh as Mike Ford walked, chugged to third on a Mike Tauchman double and scored as LeMahieu lifted a Jason Adam pitch to deep right.

"With the different looks they were able to run out there today, we were still able to push four across on a day we didn’t get a ton of hits," Boone said. "Credit to them, they mixed and matched and held us down today."