Call it unlucky No. 13.

The Wisconsin men’s basketball team was riding a 12-game winning streak against Penn State entering Saturday’s game at the Bryce Jordan Center.

But the Badgers (15-5, 5-3 Big Ten) couldn’t make it 13 straight — not after the second-half performance the Nittany Lions displayed Saturday.

Penn State (12-8, 5-4), used a late game surge to upset No. 17 Wisconsin, 56-52, marking the third time this season the Lions have topped a ranked opponent.

The Lions also defeated then-No. 18 Michigan State and then-No. 16 Illinois this season, both at the Bryce Jordan Center.

But Saturday is perhaps the Lions’ biggest win, especially considering the fashion in which Penn State pulled it out.

The Lions were down by as many as 13 points in the first half, yet conducted a stunning comeback in front of 14,292 energetic fans, outscoring the Badgers by 13, 36-23, in the second half.

Senior Talor Battle finished the game with 22 points — 20 of which came in the second half — while senior Jeff Brooks recorded 12 points and senior Drew Jones tallied 13 rebounds.