Mamadou Ndiaye added 11 points and Alex Young had 10 for Irvine (12-5), which hit 53 percent from the field and 7 of 12 from behind the arc. Nelson was 6 of 8 from the floor and missed just one of his five shots from long range.
Irvine overtook Davis (5-9) in the first half with a 14-1 run that included a pair of Nelson's 3-pointers to lead 22-10 with 8:04 left until intermission. The Anteaters never trailed again, taking a 30-25 advantage into the break and continuing to pull away over the final 20 minutes.
Josh Fox led the Aggies with 17 points and 10 rebounds.