Kareem Nitoto had 13 points and nine rebounds for the Highlanders (14-16, 7-9 Big West), who will be the No. 5 seed in next week's conference tournament. UC Riverside opens against fourth-seeded Cal Poly-San Luis Obispo in Thursday's first round.
Flowers' 3-pointer with two minutes left in overtime cut UC Riverside's lead to 69-66, but that was the last score until Martin's free throw with sox seconds left. Flowers drained a 3-pointer with two seconds remaining to make the score 70-69, but Martin added two more free throws.
Travis Souza's 3-pointer for UC Irvine with six seconds left in regulation forced the extra period.