Head coach Doc Rivers slammed the Milwaukee Bucks after their slump continued against the Toronto Raptors on Friday, saying losing to "bad teams" is inexcusable. 

The Raptors had lost 15 straight games ahead of their trip to Fiserv Forum, but Gary Trent Jr.'s 31 points helped condemn the Bucks to a surprise 117-111 defeat, their fifth loss in six games. 

Milwaukee were without Giannis Antetokounmpo as the two-time NBA MVP battles a hamstring injury, though Damian Lillard returned after three games out to score 36 points. 

However, it wasn't enough for the Bucks, who pulled within two points with 54.5 seconds left but saw Khris Middleton miss a potential go-ahead 3-pointer before four free throws saw Toronto home.

Still occupying second place in the Eastern Conference, Milwaukee are now just one game clear of the Cleveland Cavaliers and two ahead of the Orlando Magic and New York Knicks.

Each of their last three defeats have come against teams who are .351 or lower in the Washington Wizards (15-63), Memphis Grizzlies (27-50) and Toronto (24-53), leaving Rivers enraged. 

"The last three were against pretty bad teams, and to me that's inexcusable for all of us," Rivers said. 

"This is on me. I've got to figure out what we've got to do to play at a higher pace. The defense has to be better. We've got to work ourselves through this."

Lillard echoed those sentiments, adding: "These are situations where we've just got to have discipline and get the job done, and we haven't.

"But if you ask anybody in the league, they'll tell you these are some of the hardest times of the season.

"We've got to take accountability. If it was one of these games, it's alright, the next two should be handled. To have three of them is disappointing. We've just got to do better."

For the Raptors, Friday's win was their first since March 3 against the Charlotte Hornets, with stars RJ Barrett and Immanuel Quickley having both been absent in recent weeks.

Barrett had 26 points and Quickley had 25 on Friday, leaving coach Darko Rajakovic to sing their praises, saying: "It's great when we have our guys coming back and playing.

"I thought during the whole stretch the team stayed together. It's good to get a win."