WEST LAFAYETTE, Ind. (AP) Iowa's defense spent the first half chasing No. 14 Purdue on the perimeter.
When that didn't work, coach Fran McCaffrey turned up the pressure and watched the Boilermakers fall apart Saturday night.
The Hawkeyes allowed only eight second-half baskets, forced 10 turnovers and rallied from a 17-point halftime deficit to rally for a 70-63 upset and Purdue's first home loss of the season.
''We had some success with it last year, more today,'' McCaffrey said of the half-court traps he used in the second half. ''Against this team, in particular, because they're so good in half-court offense, you've got to try to go get them a little bit.''
The Hawkeyes (11-3, 2-0 Big Ten) executed the plan perfectly and managed to pull off an impressive double by sweeping two Top 15 teams this week, They beat No. 1 Michigan State on Tuesday and now have four straight wins.
Jarrod Uthoff led the way Saturday with 25 points. Peter Jok had 11 points and nine rebounds.
But the Hawkeyes won this game purely because their stifling defense, which forced Purdue (13-2, 1-1) to lose its composure.
''We wanted to be more aggressive with it, which we were,'' McCaffrey said. ''We were a little tighter, more aggressive and more active.''
It was a complete reversal from the first half when Purdue made 7 of 14 3-pointers and built a 37-20 halftime lead.
But in the second half, Purdue's shooters went cold and Iowa's usual suspects warmed up with some easy baskets. Iowa was 18 of 28 from the field over the final 20 compared with 7 of 30 in the first half.
The rest was predictable.
Iowa scored six straight to trim a 15-point deficit to nine and followed that with a momentum-changing 13-0 spurt that finally gave it the lead, 48-46 with 7:30 to play.
After Purdue tied it 48, the Hawkeyes answered with five straight points to take control. Iowa sealed the win at the free-throw line.
Kendall Stephens scored 12 points, and A.J. Hammons had 11 to lead Purdue.
''Our guards just didn't handle the basketball well and make good decisions. They were very timid,'' Purdue coach Matt Painter said. ''We had zeros turnovers against it in the first half and right as Iowa saw that (the turnovers), they got really aggressive.''
Purdue's career scoring leader, Rick Mount, raised his arms, pumped his fists and even pretended to take a shot from midcourt as fans gave him a prolonged standing ovation at halftime. The Boilermakers celebrated the return of Mount, who has had a strained relationship with his alma mater since the early 1990s. He told the crowd Purdue fans are ''the best in the country'' and implored them to stay loud for the rest of the game - and the rest of the season. Mount scored 2,323 points in three college seasons, averaging 35.4 points as a senior. He was a two-time Big Ten MVP and Indiana's 1966 Mr. Basketball Award winner.
In the first half, it seemed Uthoff was almost playing by himself. He scored 16 of Iowa's 20 first-half points. The only other Iowa players to score in the first half were Jok and Adam Woodbury, who each had one basket and two points.
While the turnover disparity didn't look huge, Purdue had 14, Iowa had nine, the Hawkeyes outscored the Boilermakers 22-7 off the miscues.
Hawkeyes: Iowa ended a seven-game losing streak at Purdue that dated to 2006. ... After going 1 of 10 on 3s in the first half, Iowa was 7 of 9 from beyond the arc in the second. ... The Hawkeyes also added to their league-leading average with nine blocks. They came into the game averaging 6.2.
Boilermakers: The Boilermakers had won 15 straight at home overall and six straight regular-season games against conference foes. ... Purdue still held its 13th straight opponent below its season scoring average. Iowa was averaging 82.6 points. ... Purdue was 8 of 26 from the field and 1 of 11 on 3s in the second half.
Iowa hosts Nebraska on Tuesday night.
Purdue hosts Michigan on Thursday night.