California was seeking its ninth title since 1973.
"I said before the game that the team that got hot would win," UC Irvine coach Ted Newland said. "We hit a hot streak there in the fourth quarter that made the difference."
This marked the fifth time the teams had met for the title. The Bears won the previous four.
"All wins are sweet but this one might be a little special," Newland said.
California led 7-6 at the end of three periods before Smoot, named the tournament's most valuable player, scored three straight goals.
Rich Ambridge cut the margin to 9-8 with 46 second remaining. A final California shot from outside was blocked.
Stanford took third place with a 7-5 victory over Pepperdine.
The matches were held at the Indiana University Natatorium.