Spain scored six points in overtime and Billy White added four points for the Aztecs, who blew a nine-point lead with six minutes left in regulation. Utah's Shaun Green forced overtime on a lay-up with 40 seconds left that tied the game at 52.
San Diego State (13-4 overall, 3-0 Mountain West) won its first three conference games for the first time since 1985 when it played in the Western Athletic Conference.
After the teams traded baskets to start overtime, White scored off his own miss to put San Diego State ahead to stay at 56-54 with 2:49 left. The Aztecs made all eight free throws in the final 1:41 as they held Utah to just two baskets in extra five minutes.
After San Diego State took a 50-41 lead with six minutes left, the Aztecs made just 2-of-5 free throws and did not hit a shot from the floor in the rest of regulation.
San Diego State stormed back from a 30-20 halftime deficit by scoring 14 unanswered points to start the second half. The Aztecs hit their first five shots, including a pair of 3-pointers by Spain, for a 34-30 lead just more than five minutes into the half.