Tennessee avoided one of the biggest meltdowns in NCAA Tournament history Sunday, letting a 25-point lead slip away before SEC player of the year Grant Williams asserted himself in overtime for an 83-77 victory over Iowa.

The biggest NCAA Tournament comeback? BYU’s 25-point rally past Iona in the First Four in 2012.

Tenth-seeded Iowa (23-12) nearly pulled off another historic comeback , sending it overtime tied at 71 — the first overtime game in this year’s tournament. The last time the teams played also was in the NCAA Tournament, with Tennessee rallying from a 12-point deficit to a 78-65 overtime victory in the First Four at Dayton in 2014.

Jordan Bohannon scored 18 for Iowa, which never led but managed to tie it twice after falling so far behind.