Melvin Eim scored 20 of his 22 points in the second half and overtime, and 17th-ranked Iowa State rallied from 18 points down to beat Northern Iowa 91-82 on Saturday for its best start in 10 years.
Georges Niang added a career-high 22 points for the Cyclones (7-0), who also snapped a 3-game losing streak against the rival Panthers (3-5).
Iowa State went on a 23-2 run midway through the second half to erase a 49-31 deficit.
But Northern Iowa's Seth Tuttle banked in a 3 with 1.3 seconds left to force OT.
Ejim responded with back-to-back 3s to put the Cyclones ahead 82-75 with 1:18 left.
Nate Buss had 23 points and Wes Washpun scored 18 with eight assists for Northern Iowa.