COLLEGE FOOTBALL : Detmer Hurt, so Colorado’s Hessler Steps In and Steps Up : Nonconference: Backup quarterback leads 29-21 victory over Texas A&M; after starter tears ligament in his knee.

It wasn’t a twist of fate that cost Texas A&M; everything from a victory to a national championship. It was a twisted knee . . . and old what’s-his-face, uh, John Hessler . . . or is it Kessler?

The third-ranked Aggies, 29-21 losers to Colorado on Saturday at Folsom Field, still aren’t positive. All they know for sure is that they probably ended Buffaloes’ starting quarterback Koy Detmer’s season and that second-teamer John Hessler essentially ended theirs.

“No, I probably couldn’t have been able to tell you,” said A&M; free safety Dennis Allen, when asked if he who knew who Colorado’s backup quarterback was. “Actually, we were really prepared to go against Koy.”

All that changed with 3:01 remaining in the first quarter and the Buffaloes facing a second and nine from the A&M; 25-yard line. Detmer dropped back, dodged one Aggie blitzer, stepped to his right, spun counterclockwise, twisted his leg, released the pass and then crumpled to the ground without having been touched. Doctors wouldn’t know for sure until after the game, but Detmer, one of the leading contenders for the Heisman Trophy, had torn the anterior cruciate ligament in his right knee.

In came Hessler, a redshirt sophomore who entered the game with only one more completion (nine) than Detmer had touchdowns (eight). His first three plays: handoff, handoff, disastrous option play and loss of eight.

Meanwhile, the Aggies were doing what they could to contain themselves. In 1990, BYU’s Ty Detmer, Koy’s brother, had both his shoulders separated by A&M; in a Holiday Bowl loss. Now this. Another day, another Detmer.

“We weren’t really thinking, ‘We got them now,’ ” Allen said, “but we definitely thought we had a little bit of an advantage.”

Instead, the seventh-ranked Buffaloes (4-0) scored all their points with Hessler in the lineup and Detmer standing on the sidelines wearing a bulky brace--available, if absolutely necessary.

Not to worry. Hessler not only recovered from a shaky start, but he scored on runs of one and three yards and dropped a perfectly thrown game-winning pass into the hands of tight end Tennyson McCarty with 14:28 left in the fourth quarter. In all, Hessler finished 10 for 20 for 177 yards and no interceptions.

“This is like a dream come true,” he said. “I never thought it could be like this.”

Aggie running back Leeland McElroy knows the feeling. McElroy, who began the day as the nation’s leading scorer, all-purpose runner and, according to a mini-poll of Heisman voters, the leading candidate for the stiff-arming statuette, was no factor. He gained only 52 yards in 23 carries. Six times he was stopped for zero or less yards. Eighteen times he gained three yards or less. His longest run was 12 yards.

“I figured they would do anything in the world to stop the run,” McElroy said.

They did. Colorado defensive coordinator A.J. Christoff stuck five players on the line and dared the Aggies to pass. Or better yet, keep handing the ball to McElroy.

“I thought it was just a matter of time,” McElroy said.

Turns out that the Aggies (2-1) didn’t have a clue how to block the five-man front. A&M; right tackle Hunter Goodwin said the Aggies didn’t anticipate the stacked approach. Right guard Calvin Collins said he thought there were “eight or nine” defenders on the line.

The Aggies, who had averaged 291 rushing yards--sixth best in the nation--were held to 74.

“We just didn’t perform,” Collins said.

Asked why, Collins stared at the ground. “I can’t tell you,” he said. “Only God knows.”

For all its troubles, A&M; overcame Colorado leads of 17-7 and 20-14 and moved ahead, 21-20, with 7:46 remaining in the third quarter. Then came Hessler’s pass to McCarty, followed about seven minutes later by Neil Voskeritchian’s 40-yard field goal against the wind to put the Buffaloes up by eight.

The Aggies still had time to score a touchdown and then try for the two-point conversion. Starting at their 30, the Aggies drove to the 49, where they faced a third-and-two.

With their national championship hopes at stake, quarterback Corey Pullig handed the ball to McElroy. One yard. Now, with only one yard to go for a first down, Colorado prepared for another McElroy run. After all, that’s what Heisman Trophy candidates do, make the key yards at the key times.

Aggie Coach R.C. Slocum had other ideas. Tired of watching McElroy get stuffed at the line of scrimmage, he called for a pass. Goodwin couldn’t believe what he was hearing when the play was called in the huddle.

“I was a little surprised that we threw the ball on fourth and [one],” he said through clenched teeth.

Pullig, playing on a sprained left ankle, rolled to his right and fired the pass wide of split end Chris Sanders.

“Just a bad throw,” Pullig said.

Meanwhile, McElroy, the Heisman decoy, stood and watched in frustration.

“We were going to throw the ball, regardless,” he said.

Colorado got the ball on downs, ran out the clock and then took its sweet time leaving the field. In what amounted to a standing ovation, Buffalo fans showered Hessler with applause. He deserved it.

On the other side of the field, Aggie cornerback Ray Mickens heard the roar. He knew who it was for.

“We thought we could rattle him,” Mickens said. “We couldn’t rattle him.”