Morgan Paige scored a career-high 33 points to lead Wisconsin to a 63-61 upset Thursday night over seventh-ranked Penn State.
Tiera Stephen scored the game-winning basket on a putback with 5 seconds left for the Badgers (2-6, 10-11 Big Ten), who stopped the Nittany Lions' 11-game winning streak.
Alex Bentley drove the length of the floor and missed a layup at the buzzer for Penn State (17-3, 7-1), which suffered its first Big Ten loss.
"We just persevered," second-year coach Wisconsin coach Bobbie Kelsey said. "The kids really believe they can win these games. "We believe they can do it and when they finally see it for themselves we can hold them to that standard now.
"We were just knocking on the door in a lot of these games and we can't break through. If we were going to break through, this was a nice one to break through on."
It's been a rough season for the Badgers who have withstood a season-ending injury to a key starter, player transfers and a six-game losing streak.
Stephen, a senior starter who averaged 10.2 minutes per game last season in a reserve role, finished with five points and a tied a career high with 11 rebounds.
Kelsey said that she had confidence with the ball in Stephen's hands at crunch time.
"I just don't like it when she picks up the ball and doesn't have a plan," Kelsey said. "Tiera has come a long, long way. Last year she was not doing any of this. She made up her mind, and regardless of what anyone said, she made up her mind this season to come in here and play basketball."
Jacki Gulczynski added 16 for Wisconsin (10-11, 2-6 Big Ten). The victory against a ranked opponent was the Badgers' first since a 48-45 win against No. 20 Michigan State on January 14, 2010.
Maggie Lucas scored 18 points and Mia Nickson added 11 for the Lady Lions, who throttled the Badgers 84-40 at home two weeks ago for their most lopsided victory since 2001.
Wisconsin raced out to a 17-6 lead in the first eight minutes of the game, but Penn State was able to chip away during a four-minute plus scoring drought. Lucas and Dara Taylor combined for seven points in a 13-0 run that gave Penn State the lead going into the break at 33-29.
Penn State led by as many as seven points early in the second half, but Wisconsin never quit. With every mini run the Nittany Lions strung together, the Badgers would answer with a key steal or basket.
Wisconsin wrestled the lead back at 55-53 when Gulczynski made a 3-pointer at the top of the key, but Lucas came back on the other end with a basket. The teams traded the lead four times with less than four minutes remaining, and Paige provided momentum in the closing minute for Wisconsin.
She made a deep 3-pointer from 25 feet to give Wisconsin a 61-59 lead with 58 seconds left, but Bentley tied the game at 61 with an off-balance jumper with 27 seconds to go.
The Badgers have relied heavily on Paige's scoring prowess this season. The junior guard, who shot 11 of 19 from the field against Penn State and 5 of 10 from beyond the arc is the team's leading scorer at 17.1 ppg. She has posted double-figure scoring in 18 of 21 games this season.
Wisconsin has weathered a tough season playing with a thin roster. Only nine players dress since two players are sidelined with season-ending injuries and another two decided to transfer.
Meanwhile, the Lady Lions, who throttled the Badgers 84-40 at home two weeks ago for their most lopsided victory since 2001, host Purdue (18-3, 7-1) on Monday with the Big Ten standings lead on the line.
Prior to the Wisconsin loss, Penn State had won 11 consecutive games since a 67-52 loss at Connecticut on Dec. 6. Penn State's start is their fastest since starting 22-2 to open the 1993-94 season.