Rob Muzzio tossed and turned until 5 yesterday morning in his bed in the Granada Motor Inn in Austin, Tex., unable to believe that a track season strewn with three pulled hamstrings, a puncture wound in a knee, tendinitis in an elbow and a deep bruise in a foot had jelled into his second consecutive NCAA decathlon championship.

"I'm injury-prone and accident-prone," Muzzio, a junior at George Mason University, said yesterday by telephone from Austin. "I haven't had more than two weeks of training without an interruption for some sort of injury since last fall. So I guess you could say this is a nice thing to have happen, considering what's been happening to me."

When Muzzio, 20, a rock-solid, 195-pound former linebacker out of Robinson High in Fairfax, drained a final 1,500 meters out of his aching body in 4 minutes 23.64 seconds late Tuesday night, he won the decathlon by five measly points -- 7,964 to 7,959 -- and became the first NCAA decathlete to win consecutive titles.

Brigham Young's Tito Steiner, a native of Argentina, won three titles, but not back to back. He won in 1977, 1979 and, after a redshirt year, 1981. The NCAA track and field championships have included the decathlon only since 1970.

Last year, Muzzio set the NCAA record with 8,227 points, winning two of the 10 events and never finishing worse than fourth in any event. His two-day performance this week was, he said, "just total ups and downs." He didn't finish first once. His highest finishes were third places in the 110-meter high hurdles and in the 1,500.

But his athletic shortcomings made for an incredibly delicious "thrill of victory" finale.

Going into the 1,500, the final event, he trailed Gary Kinder of New Mexico by 175 points. That meant he had to beat Kinder, whom he had never competed against, by 28 seconds in a 4 1/2-minute race.

"Twenty-eight seconds in the 1,500 is pretty ridiculous," Muzzio said. "I'm not known as a 1,500 runner. In fact, it probably is my least favorite event."

About 300 hardy souls remained at the University of Texas track. The lights were on. It was 10 p.m.

"By that time, you're pretty much numb. I said to myself, 'Let it go.' I just ran."

He never looked back at Kinder, who, it turns out, was hurting as much, if not more, than Muzzio. After Muzzio finished in his best time ever, he had to be helped around the track.

"I was so tired," he said.

He did not know if he had won. For 30 minutes, he sat in the grass, the other 13 decathletes sprawled around him, waiting. The timing machine got fouled up when Muzzio finished so far ahead of Kinder, although neither athlete -- nor, apparently, the machine -- knew exactly how far ahead. There was a protest, there were meetings, and then finally, starting with the 14th finisher, the results were announced.

Kinder, last in the 1,500 in 4:52.01, had his name attached to second place. Muzzio was first.

"My feeling was disbelief," Muzzio said. "It kind of proved my motto, which is that anything can happen."

And, in Muzzio's case, it usually does. Last June, at the U.S. Olympic Trials in Los Angeles, he was fourth in the decathlon after the first day (three athletes made the Olympic team), a wonderful spot for him with the discus, perhaps his best event, coming in Day 2. But Muzzio has asthma, and the often-thick air in Los Angeles got to him.

"I couldn't breathe," he said. "I started throwing up. I was up all night. I couldn't even hold down water." He withdrew from the trials the next day. Although it was a major disappointment, there likely will be two more such trials for him. Most decathletes peak in their late 20s.

In the fall came the plethora of injuries that forced George Mason to redshirt him for the indoor track season and later jeopardized his outdoor season until it was salvaged in Austin this week.

Next? Said Muzzio: "Now I'm going to relax and try to get tan and get my body parts together."