Mississippi State's Morgan William made the game-winning basket at the buzzer at the end of overtime in a huge upset.
The loss brought an end to UConn's 111-game win streak. It forced the Huskies out of the tournament, which they have won a record 11 times.
Mississippi State will now play South Carolina in the championship game at 6 p.m. Sunday in Dallas.
UConn's 111 straight wins started with a victory over Creighton on Dec. 23, 2014, and included two national championships.
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