Wisconsin went nearly 22 minutes into Wednesday’s Border Battle against the Gophers without being called for a foul.

When the officials finally whistled the No. 19 Badgers for too much contact on a rebound, the Williams Arena crowd gave them a standing ovation.

Minnesota fans heckled opposing players and the referees all night, but their team struggled to play through the no-calls. The Gophers couldn’t get into rhythm offensively against a physical, stingy and tenacious Wisconsin defense in a 56-51 loss in front of announced crowd of 14,625, the first sellout of the season.

“It’s a physical game,” said Gophers coach Richard Pitino, who wouldn’t comment on the officiating. “It’s the Big Ten. [The Badgers] have good length, good physicality. They are very, very physical.”

VideoVideo (08:02): Gophers and Badgers head coaches and players talk after Wednesday night's game

Senior forward Ethan Happ had 15 points and 13 rebounds to lead the Badgers (17-6, 9-3 Big Ten), who won their sixth consecutive game.

The Gophers (16-7, 6-6) were led by Jordan Murphy, who had 16 points on 6-for-16 shooting and 19 rebounds. Murphy was shoved to the floor on several occasions and was nearly tripped by Brad Davison on a first-half rebound. The Maple Grove native is known for taking charges and testing how much physical defensive play officials will let him get away with.

“I think more than anything it probably motivated me,” Murphy said. “… I guess the refs saw [potential fouls] didn’t need to be called. Down the stretch you just have to keep playing through it.”

In a game Pitino’s team needed to win to help boost its NCAA tournament chances, the Gophers played well enough defensively to hold their rival to 29 percent from the field in the first half, including 5-for-18 on shots inside the arc. Wisconsin shot 34.5 percent, but Minnesota wasn’t much better at 35 percent.

In the second half, Murphy’s two free throws made it a three-point game at 49-46 with 2 minutes, 11 seconds left to play, but the Gophers’ late comeback attempt was thwarted. D’Mitrik Trice made the biggest shot of the game, answering with a three-pointer with 1:44 remaining to give Wisconsin a six-point advantage.

Things really got heated when Murphy was elbowed by Aleem Ford midway through the second half, but there was no flagrant 1 call after the play was reviewed. Gophers fans were furious, but Murphy responded with a three-point play to cut a 10-point deficit to 37-34.

After Wisconsin responded, the Gophers got within 43-40 on another basket from Murphy with just under six minutes to play, but the frustration of missed shots started to set in.

Much like when the Gophers blew a 13-point second-half lead Sunday in a 73-63 loss at Purdue, Minnesota couldn’t string together enough scoring to build some momentum.

After Daniel Oturu’s two free throws with 3:13 remaining cut Wisconsin’s lead to 48-43, Pitino went with the Hack-a-Happ strategy. Happ, who has shot 47.4 percent from the foul line this season, made half of six free throws, but the Badgers were 10-for-15 in the second half at the charity stripe.

Gophers junior guard Amir Coffey, the team’s leading scorer who was averaging 19.2 points in Big Ten play, had only eight points on 3-for-10 shooting. That was a significant drop-off from his 21-point performance in the 59-52 victory against Wisconsin on Jan. 3, the U’s first victory in Madison since 2009.

Coffey’s fellow starting guards Dupree McBrayer and Gabe Kalschuer struggled as well, totaling 11 points on a combined 4-for-17 shooting.

The Gophers weren’t able to pull off their first season sweep of the Badgers since the 2008-09 season, when Tubby Smith took Minnesota to its first NCAA tournament under his coaching tenure.

For Pitino to make his second trip to the NCAAs in six seasons, Minnesota will need to pull off a few more résumé-building victories in the final eight games.

After failing in upset opportunities in their past two games, the Gophers travel to play Saturday at No. 9 Michigan State, which has lost three consecutive games.