STATE COLLEGE, Pa.—Jermaine Marshall was trapped, surrounded by giddy fans who rushed the court after witnessing Penn State's unlikely upset of No. 4 Michigan.

It was about the only time that anyone could contain the Nittany Lions' gritty guard down the stretch of the 84-78 win Wednesday night over the Wolverines.

Marshall scored 25 points and hit a key layup with 1:06 left to help Penn State roar back from a 15-point deficit to get its first Big Ten victory in more than a year.

"We have confidence in ourselves," Marshall said. "We believed we were close. It just feels good to earn that win. We definitely earned it."

Penn State (9-18, 1-14) had lost 18 straight regular-season Big Ten games dating to last season. The team's previous conference win came on Feb. 16, 2012, a 69-64 victory over Iowa.

It was Penn State's first win over a top-five team since defeating No. 5 North Carolina 82-74 in the second round of the 2001 NCAA tournament, and the highest-ranked opponent that the Nittany Lions have beaten since moving to the Jordan Center in 1996.

To celebrate, exuberant fans exchanged hugs and high-fives with the Nittany Lions.

Even Michigan coach John Beilein was impressed.

"I think what you saw tonight is why we all love college basketball," he said.

But this loss might hurt Michigan as it jockeys for seeding in the NCAA tournament. Tim Hardaway Jr. scored 19 points for the Wolverines (23-5, 10-5). Trey Burke had 18 points and six assists, but also committed six turnovers.

Michigan was uncharacteristically sloppy with 15 turnovers in the game, six more than its season average.

Penn State pounced on the mistakes.

D.J. Newbill added 17 points for the Nittany Lions, who hit a season-high 10 3-pointers. Marshall scored 19 in the second half, including four 3s that whipped the hometown fans into a frenzy. But it was his twisting drive to the bucket late left that really hurt Michigan.

The ball teetered on the rim before dropping in, causing the Penn State partisans to let out a collective sigh of relief with their team up 81-78.

"It was a chip play that we run. ... Coach put the ball in my hand and he had trust in me," Marshall said. "Fortuantely that layup rode around the rim and went down."

That was not the kind of luck that the Nittany Lions have been used to, ever since leading scorer and point guard Tim Frazier went down with a left Achilles injury four games into the season.

They had to adjust on the fly, with combo guard Newbill sliding over to the point, and Marshall needing to assume more ball-handling duties. Penn State coach Patrick Chambers, a never-say-die cheerleader, convinced his team to keep fighting through the adversity.

"Tonight, it's a relief. All the hard work, practices and shootarounds paid off for us," Newbill said.

Michigan's Glenn Robinson III misfired on a 3 with 17 seconds left. Sasa Borovnjak (nine points) had a memorable Senior Night, hitting two foul shots with 15 seconds left to seal the win.

Ross Travis provided the muscle up front with 15 points and 12 boards as Penn State made the clutch plays down the stretch.

"They beat us fair and square, and the last 10 minutes they really outplayed us," Beilein said.

Just another hard night for the league's top teams in the rough-and-tumble Big Ten.

Top-ranked Indiana lost Tuesday at Minnesota to fall to 12-3 in conference play, so Michigan squandered a chance to move into a three-way tie for second with Michigan State and Wisconsin, a game behind the Hoosiers.

"They really tried to shut down Trey. We had some good shots, but not enough good ones," Beilein said. "They slowed us up with their press a little bit, but we couldn't stop them."

Two foul shots by Marshall gave Penn State its first lead since the first half, 76-74, with 3:55 left. The Jordan Center rocked as if it were a Michigan-Penn State football game across the street at Beaver Stadium.

It was all Penn State from there.

Chambers watched as Michigan fumbled away opportunities, like when Burke had a steal from Newbill but lost control.

"The ball finally bounced our way," Chambers said. "Trey Burke strips D.J. at half court and kicks it out of bounds ... that's usually what we do."

All five of Michigan's losses have come on the road in the Big Ten—none worse than Wednesday night's defeat. Michigan finished February with a 3-4 record, heading into a showdown Sunday with the ninth-ranked Spartans in Ann Arbor.