LARAMIE -- Most of the 19,000 fans were long gone.

Most of them who stuck around did so to voice their displeasure.

They had every right to.

Still clinging to the promise shown with back-to-back home games nearly a month ago in which the Wyoming Cowboys scored 30 points, UW fans entered Saturday cautiously optimistic that their team could pull an upset over their second-biggest rival.

They were instantly stunned and quickly non-existent as the BYU Cougars ran roughshod over the Pokes, scoring on their first seven possessions and shutting out UW for a second straight season with a 52-0 rout at War Memorial Stadium on Saturday.

"It's probably the most disappointing day in my football career," UW coach Dave Christensen said. "We took steps backwards. I thought our program had improved. It's an embarrassment. I'm embarrassed and I apologize.

"It was the worst-ever game I've seen by a football team."

BYU took the opening kickoff and marched 80 yards, capping off its opening drive with a 44-yard touchdown pass to JJ Di Luigi.

They settled for a field goal on their second drive, but then found the end zone again on five consecutive drives and led 45-0 midway through the third quarter.

The Cougars had 16 first downs before the Cowboys moved the sticks twice, outgained them 543-225 for the game and BYU senior quarterback Max Hall completed 20 of 22 pass attempts for 312 yards and four touchdowns.

"This is definitely embarrassing," said UW safety Chris Prosinski, whose 16 tackles were a bright spot, if there was one for the Cowboys. "We felt like we definitely took a step back from where we've been.

"Our coaches prepared us better than this. We let them down and we let the fans down."

UW's offensive woes continued.

After scoring 30 points or more in three straight games, they now have just one touchdown in their most recent three -- and that one came on a trick play.

Outside of their final drive of the first half, in which BYU went to more of a prevent defense, and the fourth quarter when the game was well out of reach, the Cowboys totaled just 93 yards.

"It was rough from start to finish," freshman quarterback Austyn Carta-Samuels said. "They did exactly what we expected and we didn't execute, at all. There's really nothing more I can say."

Perhaps even more surprising was that the Cowboys defense had no answers.

For all intents and purposes, it held nationally ranked Utah to 16 points on the road one week earlier and shut down Air Force for most of the day in the game before that.

On Saturday, the Cougars could -- and did -- do whatever they wanted, averaging more than eight yards per offensive play.

"I don't know if [we] actually quit," Christensen said. "I never saw a great effort the entire game. You've got to start in order to quit and we never really got started."

The UW faithful never got a chance to get started, either.

They're used to booing when BYU makes the trip to Laramie.

The jeers just aren't normally directed at the home team.

Contact sports reporter Eric Schmoldt at eric.schmoldt@trib.com. Check out his blog at tribtown.trib.com/ESchmoldt/blog