The Aggies (18-8, 7-3 Western Athletic Conference) shot 57.6 percent from the field, with Nephawe going 10 of 14. DK Eldridge scored 15 points, K.C. Ross-Miller had 13 and Renaldo Dixon contributed 11.
Seattle U (11-11, 3-6) shot 43.5 percent and was 6 of 16 from beyond the arc. Isiah Umipig led the Redhawks with 24 points and D’Vonne Pickett Jr. had 18.
New Mexico State made three late shots in the first half to grab a 45-36 halftime advantage. The Aggies pulled ahead in the second with a 20-6 surge as a Nephawe jumper made it 65-47 at the 12:40 mark.
Seattle cut its deficit to nine with 6:23 left, but the Aggies responded with a 10-0 run.
The win nudged NMSU, which had lost three straight WAC road games, closer to first-place Utah Valley (14-8, 8-1), which was idle on Saturday.
The Aggies remained tied with Grand Canyon for second place. NMSU plays again Thursday at home vs. Missouri-Kansas City.