UC Davis opened up an 11 point lead in the second half but UC Irvine (16-9, 7-2) trimmed the advantage to 47-44 with 11 minutes to play. UC Irvine went up 55-53 on a Mamadou Ndiaye tip-in and play remained tight until the buzzer.
With Irvine leading 61-59, Corey Hawkins missed the front end of a one-and-one opportunity for Davis. The Aggies got the ball back following an Irvine turnover, but Darius Graham missed from long range, and with the victory UC Irvine remains atop the Big West Conference.
UC Davis (8-16, 3-6) led the Anteaters 30-26 at halftime, despite shooting only 30 percent from the field. UC Irvine shot 55 percent but committed 12 turnovers while the Aggies had only three.
Hawkins scored 19 for UC Davis.
Seton Hall sophomore Isaiah Whitehead will stay in the NBA draft and not return for his junior season.
Washington State's trio of Josh Hawkinson, Conor Clifford and Ike Iroegbu have withdrawn from the NBA draft and will play their senior season with the Cougars.
Gonzaga center Przemek Karnowski, who missed most of last season with a back injury, says he is returning for another year.