LARAMIE, Wyoming -- Jay Stoner threw for 302 yards and three touchdowns and Wendell Montgomery had seven catches for 122 yards and a pair of scores as Wyoming upset 12th-ranked Brigham Young, 31-17, in a Mountain West Conference clash.

BYU, playing in Laramie for the first time since 1992, was averaging 33 points and 440 yards. Wyoming (6-3, 3-2 Mountain West) limited the Cougars to 391 yards and held Feterik to one touchdown pass in the upset on Saturday.

The loss snapped the Cougars' six-game winning streak and prevented BYU (8-2, 5-1) from clinching the Mountain West Conference title outright while keeping Wyoming's championship hopes alive. BYU can clinch the crown, and a berth in the Liberty Bowl, with a win over Utah nest week.

"It just simply wasn't one of our better nights," BYU coach LaVell Edwards said. "They just came out and took the fight to us and sustained it throughout the whole ballgame."

"We just screwed up, a lot," BYU linebacker Rob Morris said. "We'll bounce back and get ready to play Utah and get ready to beat Utah and win a championship. We don't have any options now."

Wyoming's Jay Stoner completed 21-of-31 passes for the Cowboys (6-3, 3-2) who kept alive their slim hopes of capturing a share of the inaugural conference title by drawing within 1 1/2 games of Brigham Young (8-2, 5-1).

"I thought Stoner was particularly impressive tonight and they executed their offense very well," Brigham Young coach Lavell Edwards said.

"Our offense has grown now to where it is so versatile and we do so many things that once everybody starts stopping one thing, we can go to another and it's very difficult to prepare for," said Wyoming coach Dana Dimel.

Kevin Feterik was 30-of-46 for 362 yards and a touchdown for BYU, which saw its six-game winning streak snapped. The Cougars, who close the season with a home game against Utah, have secured no worse than a share of the title.

Wyoming needed just two plays on offense to break on top as Stoner found Montgomery with a 14-yard scoring strike. BYU knotted the contest with just under two minutes left in the second quarter when Feterik connected with Margin Hooks on a 20-yard touchdown toss.

Wyoming took the ensuing kickoff and took lead for good. Running the two-minute drill to perfection, Stoner engineered a 10-play drive that resulted in a 20-yard touchdown pass to Montgomery with 10 seconds left in the half.

The Cowboys took the second half kickoff and drove 53 yards, culminating in a 45-yard field goal by Aaron Elling that pushed the lead to 17-7. BYU answered with a field goal of their own but Stoner found Kofi Shuck in the right corner of the end zone with a 22-yard rainbow that left Wyoming with a 24-10 cushion.

Tim Beasley's 14-yard run 5:48 into the fourth quarter extended the lead to 31-10 before a one-yard run by Feterik with just under five minutes left capped the scoring.

Wyoming's Patrick Chukwurah had seven tackles, including a pair of sacks, and forced a fumble.

Hooks finished with seven receptions for 143 yards.