The Hawkeyes trailed by 25 at the half but rallied to take Tennessee into overtime.
Tennessee blew a 25-point lead against Iowa on Sunday afternoon in the second round of the 2019 NCAA tournament but held on in overtime for the win. After trailing 49–28 at the half, the No. 10 Hawkeyes launched what would have been the largest comeback in NCAA tournament history against the South's No. 2 seed.
BYU came back from 25 points in the big dance in 2012 against Iona during their first four play-in game.
After slowly chipping away at the deficit to start the second half, Iowa went on an 8–0 run with eight minutes remaining in regulation to bring the game to 64–58. Hawkeyes guard Isaiah Moss brought the game within one with a three-point jumper from the lower left corner.
Tied at 71 with 10 seconds remaining in regulation, Tennessee's Jordan Bone missed a three to send the game to overtime for the first OT of March Madness.
The Vols took an early lead in extra time and hung on for an 83–77 win to send Rick Barnes to the Sweet 16 for the first time since 2008. Tennessee's Admiral Schofield and Grant Williams posted 19 points apiece in the win, while Williams added seven boards, five assists and three blocks.
Jordan Bohannon and Moss led the Hawkeyes with 16 points each.