Butler had knocked off Maryland, Wake Forest, Louisville and Mississippi State in recent tournaments, but couldn't do the same against the Tigers.
LSU 75, Butler 71
Marcus Thornton, the SEC's player of the year, was 10-of-15 from the field and hit three of his four 3-pointers to finish with 30 points.
Purdue 61, Northern Iowa 56
E'Twaun Moore scored 17 points to help fifth-seeded Purdue get past 12th-seeded Northern Iowa.
Purdue 61, Northern Iowa 56
Northern Iowa was within two points of Purdue with 17.4 seconds left, but was forced to foul. The Boilermakers made both shots to avoid the upset bid.
Memphis 81, Cal State Northridge 70
Roburt Sallie set a first-round tournament record by hitting 10 of his 15 3-point attempts en route to a career high 35 points.
Memphis 81, Cal State Northridge 70
Northridge led by six points with 10:08 to go, but Memphis went on a 9-0 run to avoid what would have been the third No. 15 seed over a No. 2 seed since the NCAA went to a 64-team format in 1985.
Texas A&M 79, BYU 66
A&M advanced to the second round of the tournament for the fourth consecutive year thanks to a team-high 21 points by Bryan Davis (pictured).
Texas A&M 79, BYU 66
A&M made its first 10 shots and took a 22-7 lead en route to a convincing win over BYU.
UConn 103, Chattanooga 47
With coach Jim Calhoun ill and not in the building, UConn still didn't have any trouble in rolling over the Southern Conference champions.
UConn 103, Chattanooga 47
UConn will meet Texas A&M in Saturday's second-round game of the West Regional.
North Carolina 101, Radford 58
North Carolina improved to 26-1 in NCAA tournament games played in its home state and advanced to face LSU on Saturday.
North Carolina 101, Radford 58
Tyler Hansbrough (right) became the leading scorer in Atlantic Coast Conference history and finished the game with 22 points.
Maryland 84, Cal 71
Maryland never let California get going. Now the Terps are back in the second round of the NCAA tournament.
Maryland 84, Cal 71
Grievis Vasquez had 27 points and Maryland shut down the nation's best 3-point shooting team in a victory over Cal.
Washington 71, Mississippi St. 58
Quincy Pondexter and the Washington Huskies didn't go out early thanks to his season-high 23 points.
Washington 71, Mississippi St. 58
Fourth-seeded Washington took advantage of early foul trouble to Mississippi State's menacing Jarvis Varnado (32) to race past the 13th-seeded Bulldogs.
Texas 76, Minnesota 62
The Longhorns hit 11 of 20 3s to win their tournament opener for the fifth time in six seasons.
Villanova 80, American 67
Dwayne Anderson and Dante Cunningham (33) each scored 25 points, and Villanova rallied back from a 14-point hole to beat upset-minded American.
Michigan 62, Clemson 59
Michigan stymied Clemson with its 1-3-1 defense and survived a late scare in its first NCAA tournament game in 11 years.
Gonzaga 77, Akron 64
Josh Heytvelt scored 22 points - seven during a decisive late run - and the Bulldogs surged past a determined Akron team.
Duke 86, Binghamton 62
Gerald Henderson (15) and the Blue Devils weren't about to let another one of college basketball's little guys scare them again.
Oklahoma 82, Morgan State 54
Blake Griffin hit the floor hard in a tangle with Morgan State's Ameer Ali, then bounced back up and finished off another dominant performance (29 points and 13 rebounds).
UCLA 65, VCU 64
Darren Collison refused to yield in the final seconds, pressuring VCU's Eric Maynor into missing a 17-footer at the buzzer to give UCLA a one-point victory.
Western Kentucky 76, Illinois 72
A.J. Slaughter and the Hilltoppers held off a late charge to beat Illinois and knock off a No. 5 seed in the first round for the second straight year.