Connecticut pulled oft an upset over Villanova, riding Shabazz Napier's 25 points, 77-65.
Napier was on fire for the Huskies, scoring 25 despite foul trouble and a shin injury limiting his minutes. The senior hit a flurry of threes in the second half to widen the gulf.
DeAndre Daniels added 11 with three triples of his own.
Villanova got a pair of nice shooting performances in the loss. Ryan Arcidiacono and James Bell combined for 32 points, hitting six threes between them. The rest of team was off the mark, with the Wildcats shooting just 35 percent for the game.
UConn will play the winner of Iowa State and North Carolina, who play Sunday.
No. 4 Michigan State 80, No. 12 Harvard 73
The Spartans eked by after Harvard overcame a 16-point deficit to take the lead late in the second half. Laurent Rivard's three put Harvard up for the first time with under eight minutes to go in the game. But Gary Harris hit two late threes to clinch the win for Michigan State.
No. 2 Wisconsin 85, No. 7 Oregon 77
Another in a long line of exciting games this Tournament, the Badgers rallied from 12 points down to knock out Oregon. Frank Kaminsky had 19 points and Ben Brust sank four triples for Wisconsin, who reaches the Sweet 16 for the third time in four seasons.
Joseph Young had a game-high 29 points for Oregon, who allowed Brust's fourth three after failing to get a defensive rebound on three straight Wisconsin shots. The Ducks allowed 14 Badger offensive boards in the game.