Arizona Coach John Mackovic was fired Sunday, five games into the third season of his tumultuous tenure at Tucson.
Defensive coordinator Mike Hankwitz will take over as interim coach for the remainder of the season.
Athletic Director Jim Livengood offered no specific reason for the firing.
Mackovic, who turns 60 on Wednesday, survived a player mutiny last season after tearfully promising to do a better job of communicating.
But the Wildcats lost to Louisiana State, Oregon and Purdue this season by a combined 166 points to 30.
The Wildcats (1-4) lost to No. 19-ranked Texas Christian, 13-10, in overtime Saturday at Tucson.
Timmy Chang threw a Western Athletic Conference-record 70 passes and completed a school-record 42 with no interceptions in Hawaii's 41-21 victory over Rice on Saturday night at Honolulu.