The Lobos (19-11, 7-8) led from start to finish, holding off a mild BYU run in the second half to complete a regular-season sweep of the Cougars (27-3, 13-2). The Cougars played for the first time without starting center Brandon Davies, who was dismissed from the team Tuesday for violating the school's honor code, but Fredette and teammate Charles Abouo said that's not why they lost.
"They are a much better team than their record shows," said Abouo, a forward. "I felt we were ready to play this game, but I was surprised at [how poorly] we started."
The Lobos made their first four shots, took a 42-26 halftime lead and finished shooting 46 percent from the field, while holding the Cougars to 33 percent.
"They played very, very good tonight," Fredette said, after scoring 25 of his points in the second half. "And we didn't."
The Cougars' star failed to shoot better than .500 for the ninth straight game.
New Mexico's Phillip McDonald torched the Cougars with 26 points, while Drew Gordon had 16 points and 15 rebounds.
"Give them a lot of credit. They played a terrific game and came in here and beat us," said BYU coach Dave Rose.
Trailing 42-26 at halftime after shooting 24 percent from the field in the first half, the Cougars cut UNM's lead to 48-37 and had a chance to draw closer, but Fredette's open three-pointer rimmed out.
The Lobos then went on an 11-0 run to put it away, their fourth straight win over the Cougars.
New Mexico won the rebounding battle 45-29 and turned 12 offensive rebounds into 15 second-chance points. And they made 9 of 20 3-point attempts, with McDonald going 5 of 8 from beyond the arc.
"We got down early and never really got a chance to play like we wanted to play," Rose said. "We never got into a rhythm."
The Cougars were just 5 of 26 from 3-point range.
"We shot too many perimeter shots and we weren't making them," Rose said. "They were prepared for us."
BYU drilled then-No. 6 San Diego State 80-67 on Saturday, but could not muster anything near that kind of effort in front of 22,700 of their own fans Wednesday.
Abouo said the Cougars don't have any resentment toward Davies, who was replaced in the starting lineup by James Anderson. The backup had just four points and one rebound in 11 minutes.
"No resentment at all. I don't know why people would think we have any resentment for him. We love him. … Everyone makes mistakes. He didn't let anyone down," Abouo said.
R In Short • New Mexico completes a season sweep of the Cougars, stunning No. 3 BYU at the Marriott Center.
Key Moment • The Lobos jumped to a 10-2 lead and never trailed.
Key Stat • Jimmer Fredette goes 10 of 26 from the field, the ninth straight game in which he hasn't shot better than .500.