Jordan McRae led the way with 20 points for 11th seed Tennessee (22-12), which will play sixth-seeded Massachusetts in the second round Friday at Raleigh, N.C. Josh Richardson chipped in with 17 points and Antonio Barton had 10 while the Volunteers outscored Iowa 14-1 in the extra period.
Adam Woodbury registered a career-high 16 points and grabbed eight rebounds for Iowa (20-13), which led by as much as 12 early on and lost for the seventh time in its last eight games. Peter Jok had 10 points and leading scorer Roy Devyn Marble was held to seven points on 3-of-15 shooting for the Hawkeyes, who were also an 11th seed.
Iowa scored 16 of the game's first 20 before the Volunteers slowly climbed back in it by recording the final seven, capped by a McRae floater at the buzzer, to get within 29-26 at intermission. Barton drained a 3-pointer with 3:06 remaining to give the Volunteers their first lead at 59-57, but Marble answered with a three-point play.
Stokes made a free throw for a 64-62 lead before Marble tied the game on a jumper with 17.9 seconds left in the second half. Tennessee missed a chance to win it at the end of regulation, but Stokes started overtime with a three-point play, McRae made a layup and the Volunteers were on their way.
GAME NOTEBOOK: Iowa coach Fran McCaffery flew home to Iowa Tuesday night to be with his 13-year-old son Patrick for surgery to remove a thyroid tumor Wednesday morning and returned for the game. "Today's surgery for my son went as planned," McCaffery said in prepared statement. "Doctors will continue test in the coming days to determine further treatment. Patrick was in good spirits after the operation." ... Stokes notched his 20th double-double of the season. ... Iowa has not won an NCAA tournament game since 2001.