Sam Young scored 32 points as top-seeded Pittsburgh advanced to the round of 16 for the fifth time in eight years with a win over Oklahoma State.
DeJuan Blair, the powerful 6-foot-7 forward, added another double-double with 10 points and 12 rebounds.
Eric Devendorf stepped up just as Arizona State threatened to catch Syracuse.
Syracuse coach Jim Boeheim got the 799th win of his career and moved into a tie with former Louisville coach Denny Crum for seventh in all-time NCAA tournament coaching wins, with 42.
B.J. Raymond scored 15 points, 12 in the second half, and Xavier finally broke through Wisconsin's defense to pull away to a victory.
The Musketeers held the Badgers to 25 percent shooting in the second half of a 60-49 victory Sunday in the East Regional.
Arizona, a 12 seed, advanced by beating upstart Cleveland State.
Nic Wise scored 21 points to lead four double-figure scorers for Arizona.
Sherron Collins had 25 points to help lead the defending NCAA champion past 11th-seeded Dayton.
Cole Aldrich had a triple-double with 13 points, 20 rebounds and 10 blocked shots.
Travis Walton scored a career-high 18 points to lift the second-seeded Spartans to a win over USC.
The Spartans were unable to put 10th-seeded USC away until the final seconds.
Missouri rallies past Marquette in the final seconds.
Freshman Kim English scored 15 points in 4 1/2-minutes in the first half. He later came off the bench to make two free throws with 5.5 seconds left that gave Missouri the go-ahead points.
Top-seeded Louisville survived a scare from Siena to reach the Regional Semis, along with all the other No. 1, 2 and 3 seeds.
Terrence Williams led Louisville with 24 points against Siena.