UCI plays host to Cal State Northridge on Wednesday at 7 p.m. It closes the regular season Saturday at 7 p.m. at Cal State Fullerton.
UCSB (10-4-3, 6-2-1), with only one regular-season game remaining, must hope for a pair of UCI losses to retain any title hopes. UCI has 20 points (three points for a win and one for a tie), while UCSB has 19.
The Gauchos, ranked as high as No. 13, remain in the title hunt, despite playing a man down for the final 19 minutes of regulation, as well as the two 10-minute overtime periods.
UCI has defeated UCSB in each of the last two Big West Tournament title games, but is now 1-5-1 in its last seven regular-season matchups with the Gauchos.
UCI had a golden chance in the third minute of overtime, when Amani Walker got his head on a hooking Jimmy Turner free kick. But Walker's flick from about 10 yards in front rolled just wide of the left goal post.
It was only the second scoreless tie for UCI this season. The other came Oct. 16 at Cal Poly San Luis Obispo.
It was the only scoreless tie this season for the Gauchos.
UCI finished with nine shots, one fewer than UCSB.
UCI junior goalkeeper Andrew Fontein made three saves to post his 11th shutout of the season.
UCI had four of the seven shots in the first half, as Fontein was not required to make a save.
UCSB keeper Sam Hayden made three saves, including one on a rocket from about 14 yards in front on the right wing by Zach Olow. Olow's blast in the 21st minute, caromed off Hayden's chest, but the keeper recovered to collect the rebound.
UCI had another dangerous chance in the 34th minute, when Spencer Thompson slipped a pass to Amani Walker inside the 10-yard marker. Walker ran onto the pass and gave it a poke from just outside the right post. But the shot went just wide.