For four quarters on Saturday, BYU gave Southern Methodist ample opportunity to pull a stunning upset at the Cotton Bowl.

But when the Cougars found themselves trailing by three points in overtime, on a day when they could do little right offensively, they weren't about to try anything fancy.Instead, they placed the ball in the hands of running back Brian McKenzie, whose 15-yard touchdown gallop - it was the longest run from scrimmage by either team all day - ended the game. And No. 23 BYU escaped the Cotton Bowl with a 19-16 triumph over the Mustangs.

In the minds of Cougar coaches, there was no doubt what the strategy would be in the must-score situation. "The tighter the game gets," BYU coach LaVell Edwards said of McKenzie, "the better he becomes."

McKenzie took the handoff, ran off-tackle and then through a gaping hole created by offensive linemen Eric Bateman, Matt Cox and Jason Andersen. Then he broke a couple of tackles and danced into the end zone. "I sawthe seam and I hit it," said McKenzie, who totaled 98 yards on the day. "I saw the goal line and I knew there was nothing that was going to stop me."

For most of the game, though, the Cougars did everything imaginable to stop themselves from crossing the goal line. An opportunistic SMU team turned two fumbles and an interception into scores, and as a result, the Mustangs threw a major scare into BYU.

"We dodged a big (bullet)," said cornerback Ben Cook. "We're lucky to get out of here with a win."

All week long, Edwards had warned his team to guard against a letdown after an emotional victory over Arizona State last Saturday. "It didn't surprise me at all that it was a tough game," said Edwards. "I'm not displeased at all."

The Mustangs, on the other hand, were devastated, knowing they could have knocked the Cougars off their WAC throne.

SMU owned the upper hand in overtime, as a field goal gave the Mustangs a 16-13 advantage, only to watch McKenzie drive through their defense and drive a stake through their hearts.

"I'm disappointed. I'm not here to win moral victories over ranked teams," said SMU coach Mike Cavan. "We played hard, I know that, but we still have to play better if we want to win football games. We'll learn to reach down into our guts and win football games."

The Cougar offense sputtered throughout the game, but the Mustang defense was one reason why. SMU sacked quarterback Kevin Feterik five times and, for the most part, thwarted the Cougars' aerial show. The Mustangs played zone in the secondary and effectively clogged the passing lanes.

"I don't think their passing attack was a big part of their game today," said cornerback Jacoby Rhinehart, who picked off Feterik early in the second half when he stepped in front of BYU receiver Margin Hooks.

Eight plays later, kicker Roy Rios booted a 27-yard field goal and suddenly, SMU had a 10-6 lead with 10 minutes remaining in the third quarter.

In the fourth quarter, Feterik and Hooks struck back when they connected on a 32-yard touchdown pass. Hooks ran a post pattern, streaking past the Mustang defenders. Feterik spotted the Waco, Texas, native and delivered a perfect strike. Following Owen Pochman's extra point, BYU reclaimed the lead at 13-10.

"They weren't giving us the post, except for that one play. They weren't letting us get anything deep," explained Feterik, who finished 22-of-30 for 216 yards.

From the outset, the Cougars looked less-than-sharp offensively. On their second possession of the game, the Cougars had the ball at the SMU 48 but advanced just 19 yards. Pochman wound up drilling a 47-yard field goal to put BYU up 3-0, which is the way the first quarter ended.

On the first play of the second quarter, the Cougars gift-wrapped a scoring opportunity for the Mustangs when Dustin Johnson fumbled a handoff in the backfield. The ball was picked up by defensive end Luke Johnson, who rumbled to the BYU 24.

Minutes later, SMU scored its only touchdown of the day, on a five-yard scoring toss from quarterback Chris Sanders to receiver Jimmy Moore to take the lead, 7-3.

Pochman added a 41-yard field goal later in the quarter, and SMU went to the locker room with a 7-6 edge. "We knew then we were in a dogfight," said Feterik.

SMU continued to pressure the Cougar QB in the second half, and a leaping interception by Luke Johnson with 4:40 left in the game put the Cougar defense in a bind once again. The Mustangs drove 37 yards to the BYU 10-yard line before settling for a field goal that tied the score at 13 with 48 seconds remaining.

In overtime, after a 17-yard completion from Sanders to Rafiq Cooper, SMU had a first down at the BYU 13. Sanders missed receivers in the end zone twice and the Mustangs once again settled for a field goal. Rios hit a 28-yarder, putting the pressure squarely on the Cougars, who took over on the 25- yard line.

Almost everybody in the Cotton Bowl expected the Cougars to throw the ball. "I thought we were going to pass, and I think SMU expected us to pass, too," said tackle John Tait.

"We didn't expect them to run," SMU's Johnson admitted. "They had some success with it, so I guess I shouldn't have been surprised."

On first down, McKenzie picked up five yards, and five more on second down. With first down from the 15, BYU called his number again, even though McKenzie was exhausted - he'd carried the ball 20 times already. "I was tired," said McKenzie, "but I didn't want to go home with another loss."

His burst into the end zone boosted BYU's record to 2-1 overall and 1-0 in the WAC. SMU fell to 1-3 and 0-1.

The Cougars host Utah State on Friday night, and the Mustangs will travel to New Mexico on Saturday.