UNLV quarterback Rocky Hinds threw for 144 yards on 18-of-36 for the Rebels (1-10, 0-7), who have lost 10 straight.
Wyoming, which never trailed, jumped to a 20-3 lead highlighted by two touchdowns. The first came on a fake as running back Ivan Harrison threw an 18-yarder to Tyler Holden with 11:59 left in the first quarter. Sween then had a 1-yard sneak with 6:32 left in the half.
The Rebels cut the lead to 20-10 on a Hinds 2-yard touchdown pass to Ryan Wolfe in the left side with 1:59 left.
Sween upped the lead to 27-10 on a 5-yard pass to Wade Betschart in the third quarter. A 3-yard touchdown run by Moore with 1:01 left in the third made it 34-10.
UNLV scored two fourth-quarter touchdowns, making both two-point conversions. The first came on a fake run as wide receiver Ryan Wolfe threw an 18-yard pass to Casey Flair with 12:39 left. With 9:38 left, Chris Brogdon recovered a blocked punt by Rod Smith from 4 yards, cutting it 34-26.
The Cowboys stopped the Rebels' final possession at the Wyoming 29-yard line with 2:40 left.