PROVO — Only one Mountain West Conference team has been able to beat No. 3 BYU this season.

It's the Cougars' nemesis, New Mexico, which invades the Marriott Center tonight (8 p.m., The Mtn.)

"We know these guys are going to come in and be ready to go," said Cougar guard Jimmer Fredette. "You don’t get many opportunities to play a top-3 team in the country. They realize that and they know it would be a huge win for them if they could get in here and get a win. We've got to try to prevent that."

BYU (27-2, 13-1) is fresh off a monumental 80-67 victory at then-No. 6 San Diego State last Saturday. The last time the Cougars faced the Lobos, BYU had just experienced a similar, high-profile 13-point win over the Aztecs. UNM rallied from a 13-point second-half deficit to record a 86-77 upset in Albuquerque.

The Cougars, ranked in the top five for the first time in 23 years, are guarding against history repeating itself.

"Sometimes games go like that," Fredette said of the game at The Pit. "They're a tough team in their place. They were very up to play us. We were a top-10 team going in there and they wanted to beat us more than we wanted to win. We have to be careful of that because, last time we had a big win against San Diego State, we went there and lost. We've got to not let that happen again."

With a win tonight, the Cougars can clinch at least a share of the outright Mountain West Conference championship. But the Lobos (18-11, 6-8) likely won't make it easy. UNM is gunning for a second consecutive season sweep of BYU. In fact, the Cougars have lost three straight games to the Lobos, dating back to last season, and four of the last five meetings. The last time BYU beat New Mexico was a little more than two years ago.

"New Mexico's a very good team," said BYU swingman Charles Abouo. "They're really tough. They do a lot of different things well and they're really versatile. They can shoot with you, they can run with you, they can slow it down. They're big and athletic. They're very skilled. And they have a great coach. So they're a tough matchup. We're aware of their success against us the last couple of years. To us, this game is as important as any game we've ever had with our group here. … We're going in wanting to win this game really bad."

The Cougars tend to have matchup troubles with UNM, said BYU coach Dave Rose.

"This team is good," he said. "They have a great point guard and good inside players who can really shoot it. They caused us a lot of problems last time we played them."

For BYU, one of the keys will be defending senior Lobo point guard Dairese Gary, who scored 26 points in an overtime loss to UNLV a week ago. Last Saturday against TCU, he poured in a career-high 32 points and had nine assists.

"He's just a special player," UNM coach Steve Alford said of Gary. "He has taken a lot of the burden, and I wish we could have gotten him some more wins this year, but he's a senior surrounded by a lot of young guys, and he's having an incredible year."

Gary recorded a double-double (14 points, 10 assists) against BYU last month. In his last four games, Gary is averaging 24.3 points and shooting 65 percent from the floor.

"He's a very good player and he really penetrates well," Fredette said. "We've had trouble in the past getting him stopped. He really gets up for games against us. He knows he needs to play well and he knows that we're a good team. He's had our number these last couple of years. … Hopefully we can slow him down a little bit."

Gary makes his teammates better, Rose said.

"They've always got three or four good shooters on the floor," he said. "That spreads you out and allows Dairese to have a lot of space. He's great operating in space. (Forward) Drew Gordon really gives them a lift inside. They've got the pieces at every position — they've got great shooters, a really good point guard who's a great senior leader, and a good inside game. It's a challenge."

Six of the Lobos' eight conference losses have been by six points or fewer.

"They fight you right to the end," Rose said. "That's what we expect on Wednesday."

NOTABLE: With 25 points against San Diego State, Fredette now has 2,324 career points, surpassing Michael Smith to become No. 2 on the school scoring charts. Smith scored 2,319 points. Fredette needs 144 points to eclipse BYU's all-time leader, Danny Ainge, who scored 2,467 points. … Rose is 154-42 in his six seasons at BYU and is the program’s all-time leader in winning percentage at .786. … When asked if BYU deserves a No. 1 seed in the upcoming NCAA Tournament, Alford replied, "There's no question in my mind."

Cougars and Lobos on the air

New Mexico (18-11, 6-8) at No. 3 BYU (27-2, 13-1)

Wednesday, 8 p.m. Marriott Center

TV: The Mtn.

Radio: 1160 AM, 102.7 FM