TORONTO — A second loss to the Milwaukee Bucks, and a slumping Kyle Lowry.

On a night that shone a spotlight on Lowry's offensive struggles, the Bucks topped Toronto 104-99 on Sunday, becoming the first team to beat the league-leading Raptors twice this season.

Lowry had zero points and three turnovers, and moments after the narrow loss, the four-time all-star sounded puzzled by his performance.

"I've gotta look at the film, see where it was at," Lowry said quietly. "I don't know. Just couldn't find the open ones tonight."

Kawhi Leonard, who had 20 points on the night, said it's only a matter of time before Lowry gets his offensive groove back.

"I feel like he should be a little bit more aggressive. Our offence allows everybody to be themselves and take their shots. It's a lot of freedom. With that said, he's gonna have some big games coming up," Leonard said.

"I think he's been shooting it good, it's just the ball hasn't been falling for him. We're still in the games late with him struggling with shooting. He's just got to keep being himself and they're going to fall."

Serge Ibaka led the Raptors with 22 points, Fred VanVleet added 19 points, and Pascal Siakam finished with 17.

Giannis Antetokounmpo had 19 points and 19 rebounds, while Brook Lopez had 19 points to lead the Bucks (17-8), who are second in the East.

The Raptors had hoped to gain a leg up on what could be an Eastern Conference post-season opponent, particularly after suffering their first loss of the season to the Bucks, 124-109 on Oct. 29 in Milwaukee. Neither Leonard (rest) nor Antetokounmpo (concussion protocol) played that night.

But it was the Bucks who led for much of the night, taking a 79-74 advantage into the fourth quarter, and stretching it to 11 points less than 90 seconds later.

But when Ibaka drilled a three-pointer with 5:18 to play — then raised his arms to the fans, signalling them to cheer — it pulled the Raptors to within three points.

A three-pointer from VanVleet, then one from Leonard that bounced off the far side of the rim before falling through the hoop sent the Raptors into the edge-of-your-seat final two minutes with a 97-94 lead.

Malcolm Brogdon quieted the crowd with back-to-back threes to give the Bucks a three-point lead. A VanVleet basket made it a one-point game, but Antetokounmpo drove to the hoop for a dunk with 12 seconds to play that sealed the Bucks' victory.

"To go on the road and play the top team in our conference and have it go down to the wire and find a way to win is a great win for the team," said Bucks coach Mike Budenholzer.

Lowry is in the midst of a rough stretch, coming into the night shooting a woeful 8-for-37 in four previous appearances. It was more of the same Sunday.

Do his teammates feel more pressure shouldering the scoring load?

"I don't know if it puts the pressure on them to play perfectly," coach Nick Nurse said. "We didn't get anything out of (Lowry) offensively, again. I thought he played a pretty tough game and did some good things. I think we got a lot of really good offence tonight."

Most of Lowry's shots during this stretch have been from behind the arc. All five of his shots Sunday were three-point attempts.

"I think we need some of his paint touches," Nurse said. "He's driven in there and kicked it out to some open guys a lot because they're really giving him a lot of attention. But somehow, we have to get him to bulldoze his way in there and get to the rim and get so me paint shots or at the rim shots."

Lowry agreed.

"Yeah, I've got to," he said. "I was thinking about that tonight, and I just didn't get an opportunity, or just didn't do it, rather. I've got to be a little bit more inside the paint, inside the arc. I definitely do."

The Raptors were coming off a 106-105 overtime loss in Brooklyn on Friday.

Milwaukee's newest acquisition George Hill didn't play Sunday. In a move that signalled a serious playoff push, the Bucks acquired the backup guard from Cleveland on Friday in a three-team trade.

The Scotiabank Arena fans included Max Holloway, who beat Brian Ortega on Saturday night to win back-to-back UFC featherweight titles, and Max Kerman and Mike DeAngelis of the Arkells.

The lead changed hands five times in the first quarter before the Raptors cobbled together an eight-point advantage late in the frame. They took a 30-25 lead into the second.

The Bucks opened the second quarter with a 7-0 run, and a three-pointer by Ersan Ilyasova put Milwaukee up by eight. The Raptors chipped away at the difference over the frame's final five minutes, and trailed 51-49 at halftime.

The Raptors' tough stretch of games doesn't let up. They now head west for four games beginning Tuesday against the Clippers in L.A. They'll travel to Golden State, Portland and Denver before returning home to host Indiana on Dec. 19.