Paul Watson added 10 points, 11 rebounds and four steals for Fresno State (14-15, 9-7 Mountain West). The Bulldogs led 46-36 with 10 minutes left.
Deshawn Delaney's free throw pulled New Mexico (14-15, 6-11) within 55-53 with a minute to go. Harris made 1 of 2 to give the Bulldogs a three-point lead with 28 seconds.
Fresno State opened with a 30-8 lead, but the Lobos answered with 13 straight points and closed within 32-25 at halftime.
Delaney led the Bulldogs with 15 points. Obij Aget had 13 points, 12 rebounds and four blocks.