Just when WKU was building steam, they ran out of it Thursday night.

The Toppers (9-12, 4-5 Sun Belt Conferene) fell flat in front of 3,182 fans in Diddle Arena, breaking a four-game winning streak with an 80-76 loss to South Alabama.

“We didn’t have the energy, and we didn’t have the leadership consistently,” Head Coach Ken McDonald said. “We had it for a short stretch there in the second half when we came back and put ourselves in position to steal one, because we didn’t have close to the 40-minute effort we’ve had the past two weeks.

“It’s difficult to swallow because we’ve come a long way in a short time, but that’s reality right now.”

Two of WKU’s biggest strengths during its four straight wins was defense and free throw shooting, and both disappeared on Thursday.

The Toppers made just 11-of-22 free throws, and they allowed South Alabama (10-11, 4-6 Sun Belt) to make 10 3-pointers and shoot 55.6 percent from behind the arc.

“It’s very disappointing, not to have the energy in front of a home crowd to get a win,” senior forward Steffphon Pettigrew said. “We had a good stretch — four-game winning streak — and we come out and play like this. It’s very disappointing.”

The Jaguars’ dynamic duo of guard Martino Brock and center Augustine Rubit didn’t even inflict the biggest damage to WKU.

It was guard Gary Redus, who came into the game averaging eight points per game, that made 5-of-6 3-pointers and scored 26 points.

“They pretty much did whatever they wanted,” McDonald said. “They shot the ball uncontested, they got the ball to the rim at key points in the game. They just put their head down and drove, and we couldn’t guard the drive.”

The Toppers entered halftime down just 33-31 despite shooting 35.5 percent from the field, due in large part to the efforts of sophomore guard Caden Dickerson.

Dickerson tied a career high with 15 points in the first half, including three 3s, but was held scoreless after the break.

“They were just leaving me open, and my guys were getting me good shots,” Dickerson said. “I was just trying to knock them down in the first half. In the second half, they took those away, but we were able to go inside more.”

A basket by senior forward Juan Pattillo gave WKU a 44-40 lead — its largest of the game — with 15:36 left in the game, but a 13-4 run by South Alabama gave the Jaguars the lead for good.

Redus scored eight points during the pivotal run, including two 3-pointers.

The Toppers pulled within one at 75-74 with 1:58 left but couldn’t convert several chances to tie or take the lead.

Dickerson missed a layup, and Pattillo missed three free throws before South Alabama’s Allyn Cooks netted a jumper to extend the lead.

With WKU down 78-76 with eight seconds left, Redus made two free throws to secure the win.

“This is Sun Belt play. You can’t all of sudden decide you want to come play in the second half,” Pettigrew said. “You’ve got to play from the beginning and come ready to play.”

Senior forward Sergio Kerusch finished with 18 points and 11 rebounds, scoring his 1,000th career point in the process. He’s the 46th player in WKU history to reach the milestone.

Pettigrew had 18 points and eight rebounds, and Pattillo added 16 points and nine rebounds.

That was big production from three of WKU’s seniors, but McDonald said he was still disappointed in his senior class — including reserve forward Cliff Dixon — for not having the team ready to play.

Pettigrew didn’t disagree.

“I can take a lot of blame,” he said. “I haven’t been showing the leadership I should. I was a little bit down, and when my body language gets down, it affects the whole team.”

WKU shot 43.3 percent from the field but allowed the Jaguars to shoot 53.4 percent.

The Toppers out-rebounded South Alabama, 41-33, and grabbed 21 offensive rebounds on 38 missed shots. That led to 24 second-chance points.

But McDonald said not even the success on the glass could cover up WKU’s other deficiencies.

“I worry about everything,” he said. “That’s our job, and you could psychoanalyze every little part of what happened tonight, but we’ve been putting together more of a 40-minute effort, and that’s been good to us. I don’t know why we would get away from that.”

WKU has a short turnaround, hosting Louisiana-Monroe at 3:30 p.m. Saturday.

McDonald said that with the hole the Toppers have dug for themselves, every game is big at this point.

“It’s disappointing because in the last two weeks, we’ve figured it out a little bit,” he said. “Not that we’ve been playing perfect, but we were going in the right direction. And now you’ve got to go back out in 24 hours and get this taste out of your mouth and change the momentum.”