MILWAUKEE – Wisconsin entered the 2014 NCAA men's basketball tournament a popular pick to reach the Final Four for the first time under Bo Ryan largely because the Badgers feature a more dynamic and diverse offense than previous teams.

So how did Wisconsin, seeded No. 2 in the West Regional, overcome an early seven-point deficit against No. 15 American University on Thursday at the BMO Harris Bradley Center?

With defense, of course.

Wisconsin held American (20-13) to a season-low total in points and only 37 field-goal attempts en route to a 75-35 victory in the second round in front of a pro-Badgers crowd announced at 17,749.

The Badgers (27-7) closed the first half with a 19-3 run to establish a 32-22 halftime lead and then opened the second half with a 21-3 run to push the lead to 53-25 with 11 minutes, 6 seconds left.

Wisconsin's 40-point margin of victory was a program record in an NCAA tournament game. The previous mark was 24, set in 2012 against Montana.

"It is great that we can win in different ways," Badgers junior guard Josh Gasser said after contributing seven points, four assists and sticky defense on American guard Jesse Reed. "This year's team, yeah, we can score a little bit better. But still we pride ourselves on the defensive end."

Wisconsin, which lost its opening NCAA tournament game last season, advances to face No. 7 Oregon (24-9), an 87-68 winner over No. 10 BYU.

The Eagles, whose previous low point total was 44, had three second-half field goals — with 19:04 left, 5:19 left and 2:16 left.

"People talk about our offense but our defense [transitions] so well into our offense," Wisconsin forward Sam Dekker said. "When we get stops and we're focused on defense, we're so much better on offense."