No. 14 Kentucky happily took advantage, holding on for a 66-60 victory after itself having a sluggish second half.
Thompkins may be the front-runner for SEC player of the year, and Leslie joined him on the preseason all-SEC team. But neither showed up at hallowed Rupp Arena on Saturday.
Thompkins had a season-low nine points. Leslie had five points, his lowest in SEC play.
Teammates like Dustin Ware (18 points) tried to pick up the slack, but this game showed that Georgia needs its stars.
"It was just one of those nights for our two best scorers," Ware said. "You'll rarely see that happen with them two."
It was not a back-breaking loss for Georgia (14-6 overall, 3-4 in the SEC). While the Bulldogs are falling out of the SEC East race, they still have plenty of chances to play themselves into an NCAA tournament bid.
But they have now dropped three of their last four, and four of their last six since their Jan. 8 win over Kentucky at Stegeman Coliseum.
And while Kentucky (16-4, 4-2) played like a team bent on revenge during the first half, it left the door open in the second half. Georgia didn't take advantage.
Twice in the final three minutes, when the once 17-point lead was down to six, Thompkins missed open 3-pointers. He also missed an open baseline jumper during that stretch.
As for Leslie, the lingering image of his game was a failure to throw down an open alley-oop in the second half. The junior forward, known for his highlight dunks, was 0-for-5 from the field, scoring all his points at the free throw line.
"When Travis misses a lob at the rim you just know it's not his night," Georgia head coach Mark Fox said. "It's hard for us to win when those two kids are both having tough nights like they did today."
Thompkins, who was wearing a shin guard on his right leg, said he bumped his shin in a practice. But he answered "not at all" when asked if it affected his game.
"No I'm fine. I was just a little off today," he said.
"My teammates need me to score. When I'm not making shots then it hurts our team," Thompkins said. "I understand that, and we all as a unit understand that. We'll just find other ways to put the ball in the basket."
While Thompkins missed shots, Leslie simply disappeared for long stretches.
"I was feeling good coming into the game. I really don't know what happened. I couldn't, my shot wasn't falling. I just wasn't on my game today."
Fox left each player in the game, and continued to call plays for them. He felt he had no choice.
"They've been so good that they deserve to play through a tough night. We just couldn't get either one of them going.
While each player said there was no malady affecting them, Fox indicated he thought something else might have affected the entire team.
There might have been a hangover from Tuesday's double-overtime loss to Florida, which Georgia almost won in the first overtime. Fox said the team's poor first half at Kentucky indicated to him that: "I don't think we put it all behind us."
He called timeout at the 17:08 mark of the first half, after Kentucky got out to a 9-2 lead.
"I saw early signs that we weren't where I wanted us to be. We had two turnovers early, we can't play that way," Fox said. "I just was really concerned with our mentality and our level of execution."
The Bulldogs finished stronger, thanks mostly to the efforts of Ware and Gerald Robinson. But in the final minute, when it was a seven-point game, the Bulldogs committed two straight turnovers.
"I knew we would take our lumps in the conference," Thompkins said. "I'd definitely like to be on the other end of things, but we've got more games to play and we'll see how it pans out."