TORONTO - A glorious, cloudless summer afternoon north of the border just might have cost the Yankees a sweep.

Carlos Beltran lost a routine fly ball in the sun in the third inning Sunday afternoon, and the bad break changed everything for Luis Severino.

The rookie righthander, who had been coasting, seemed to lose focus for the next two batters -- and Josh Donaldson and Jose Bautista made him pay in the Yankees' 3-1 loss to the Blue Jays in front of a sellout crowd of 46,792 at Rogers Centre.

Instead of a 1-2-3 inning, Severino had to face Donaldson with Troy Tulowitzki on second. He singled and Bautista followed with a two-run homer to give the Blue Jays a 3-0 lead.

"I lost it when it was close to me," said Beltran, who won Friday night's game with a pinch-hit three-run homer in the eighth inning and also homered Saturday. "If I would have seen it, I would have caught it. The ball got into the sun and I just couldn't make the catch."

Still, the Yankees (64-52) left Toronto with a half-game lead after arriving a half-game behind. They start a 10-game homestand Monday against the fading Twins, who will be followed into town by the Indians and Astros.

"We did what we had to do," Alex Rodriguez said. "We came in and we won two out of three. Now we get to go home and play at home 10 games so that's good for us."

The 21-year-old Severino, deemed untouchable at the trade deadline by general manager Brian Cashman, was good again Sunday in his third career start.

"I felt that promoting him, we'd probably get at least as good a performance from him as we would from most trade candidates," Cashman told Newsday's David Lennon after Sunday's game.

Severino came in having allowed a combined two earned runs in his first two starts but had suffered from a lack of run support, getting just one earned run in those outings.

It played out that way Sunday as Toronto righthander Drew Hutchison shut out the Yankees over 5 2/3 innings before Jacoby Ellsbury's homer cut the Bombers' deficit to 3-1.

Severino allowed three runs, five hits and three walks with nine strikeouts in six innings.

"It's pretty impressive to watch what he's done," Joe Girardi said. "He's rose to the occasion."

The Blue Jays (65-54) scored three sun-aided runs in the third. Severino retired the first two batters before Troy Tulowitzki, who struck out looking at a 97-mph fastball in the first, lifted a fly ball to medium right. Beltran settled under it but lost it at the last moment, putting his arms in front of him in self-defense as the ball nipped him on the side. The play was scored an error but later changed to a hit.

"I just hoped to get out of the inning and nobody would score," Beltran said.

Instead, a Blue Jays offense mostly held in check the first two games, pounced.

Donaldson lined an RBI single, on a 1-and-2 slider, to right to make it 1-0 and Bautista followed by crushing a 2-and-1 slider to left-center for his 28th homer of the season and a 3-0 lead.

"That's part of the game," Severino said through a translator of the ball Beltran lost.

Of the Bautista homer, he said: "It was supposed to be a slider down but it stayed up and I paid for it."

But overall, the weekend could only be characterized as a positive. There was Friday's eighth-inning rally, Masahiro Tanaka's dominance Saturday and Severino shrugging off the pressure of being inserted smack in the middle of a pennant race.

The Yankees have seven games left against Toronto, none until Sept. 10 at the Stadium.

"It's two very competitive teams that played hard against each other and pitched well and runs were at a premium and they were good games," Girardi said. "What does it tell me moving forward? I don't know because we don't play them again for a while but you have two pretty good teams."