Wallace had 14 first-half points, including two four-point plays in the span of 2:35. Bellfield was 6 of 7 from the field and had five assists for UNLV (10-1), which only had seven turnovers.
Nick Schneiders led the Spartans (1-9) with a game-high 22 points, 7 rebounds and 5 blocks. Schneiders was one point shy of his career high.
UNLV was without leading scorer Tre'Von Willis, who sprained his right ankle two days earlier in a win over Weber State in Las Vegas.
The Rebels never trailed, jumping to a 29-9 lead. They led at 50-31 at halftime. The lead grew to as many as 32 with 5:14 left.