The Huskies (15-11, 5-8) became the fourth team to knock off one of the Big East's top teams with a win they desperately needed in coach Jim Calhoun's second game back on the bench after missing 3 1/2 weeks on a medical leave.
On Friday night, then-No. 5 West Virginia lost to Pittsburgh in triple overtime. On Sunday, Louisville beat then-No. 2 Syracuse and Rutgers beat then-No. 7 Georgetown.
The Huskies made it four in as many days by shooting 67 percent from the field and 80 percent from the free throw line in the second half while holding Scottie Reynolds of the Wildcats (22-3, 11-2) to four of his 18 points.
Connecticut was coming off a 60-48 loss to Cincinnati. The Huskies hit the 48-point mark less than four minutes into the second half Monday.
Calhoun had called the loss to Cincinnati "embarrassing." This had to wipe some of that feeling away.
Reynolds, the conference's fourth-leading scorer at 19 points per game, had been a second-half star for the Wildcats in their recent games. With Jerome Dyson moving with him all over the court, the senior guard managed just the four points on 2-of-6 shooting, including missing all three 3-point attempts.
The Huskies hit their first seven shots of the second half and turned a 36-35 halftime lead into 55-48 lead. They were up 67-58 with 5:30 left and then matched almost every Villanova score, going 13-of-16 from the line the rest of the way.
Reggie Redding hit a 3 with two minutes left to bring the Wildcats within 76-69 and the crowd of better than 18,000 at the Wachovia Center was suddenly alive in the matchup of teams from last season's Final Four that were on very different paths this season.
Connecticut milked most of the 35-second clock and Walker was fouled with three seconds left. He made two free throws with 1:26 on the clock. Dominic Cheek hit a 3 for the Wildcats with 1:15 to play to make it 78-72 and this time Connecticut again worked the shot clock down to two seconds and Walker was able to get off a 3 that missed. Gavin Edwards corralled the rebound for Connecticut and that turned into one of two free throws for Dyson with 35 seconds left for a seven-point lead.
Dyson had 15 points and six assists for Connecticut. He was 9-of-14 from the free throw line and Walker was 14-of-16 as the Huskies finished 35-of-44.
Corey Fisher had 14 points for the Wildcats, who could have moved one game ahead of Syracuse in the conference race. The Huskies, who had lost five of six, remained 12th in the 16-team league and ended a six-game road losing streak in the Big East.