BOULDER, Colo. (AP) -- Idled a week ago because of migraines that were believed to be the aftereffects of a concussion, Mike Moschetti proved to be a major headache for Oklahoma (unranked ESPN/USA Today, No. 24 AP) on Saturday.

Moschetti passed for four touchdowns and ran for another, and an aggressive Colorado defense had four interceptions as the Buffaloes upended Oklahoma 38-24.

Moschetti completed 22-of-31 for 382 yards, including 49- and 88-yard scoring tosses to Javon Green.

Colorado (5-3 overall, 4-1 Big 12) generated 537 total yards and held Oklahoma's prolific "spread" offense in check most of the day. The Sooners, who boasted the nation's third-best passing attack and who had exceeded 500 total yards four times this season, were limited to 317.

Besides the four interceptions -- two by cornerback Ben Kelly -- the Buffaloes sacked Josh Heupel three times.

"Today was probably as good as we could play in most respects," Colorado coach Gary Barnett said. "That was just a great effort from the heart. I challenged our guys to play that way. Mike Moschetti played particularly well, and I thought we had a great defensive plan. We went after them. We swarmed and had great pressure."

Oklahoma coach Bob Stoops agreed.

"Colorado really flew around and made a bunch of big plays, on both sides of the ball," Stoops said. "Their defense didn't do anything unorthodox. They just changed up their coverages and made plays. They had a four-man rush most of the day. They blitzed quite a bit on first down and played man (coverage).

"We were just terrible mentally. We had too many penalties and busted assignments. We threw an interception on a screen pass at the goal line. We didn't give ourselves a chance to win."

Oklahoma (4-3, 2-2) led briefly at 3-0 and 10-7 in the first half, but Kelly's two interceptions -- both coming in the first three minutes of the third quarter -- set up 10 points for a 24-10 lead.

Heupel threw two touchdown passes in the fourth quarter, but each time Colorado countered with a score of its own.

"There were times in the game when we had to score because of Oklahoma's offense," Moschetti said, "and we went down the field and scored. That's what I'm most proud of."

Sooners receiver Jarrail Jackson turned a screen pass into a 50-yard gain on the final play of the third period. Four plays later, running back Reggie Skinner caught a 6-yard shovel pass from Heupel, cutting the deficit to 24-17 with 14:02 remaining.

Moschetti promptly scrambled for a 23-yard gain to ignite an eight-play, 80-yard scoring drive capped by his 14-yard TD pass to tight end Daniel Graham with 10:29 left.

On fourth-and-9, Heupel hit Jackson, who had beaten Kelly deep, for a 49-yard scoring play with 8:37, making it 31-24.

The Buffs scored again, however, just 39 seconds later. When cornerback Pee Wee Woods fell down, the wide-open Green caught Moschetti's pass down the left sideline and went 88 yards for the score.

Two subsequent Oklahoma possessions ended on another interception and an incomplete pass on fourth down.

Heupel completed 26-of-58 for 328 yards.

"Their pressure bothered me all day," Heupel said. "They constantly had someone in my face, and they knocked me down quite a bit. We didn't think they were going to blitz that much."

Colorado lost its leading rusher, Cortlen Johnson, to a sprained medial collateral ligament in his right knee in the first quarter.

Sooners defensive end Cornelius Burton suffered a neck injury early in the fourth quarter. Burton was assisted by medical personnel for about 10 minutes, was removed from the field strapped to a gurney and was taken to a hospital for X-rays. A team medical official said Burton had movement in his legs.

Moschetti's first two TD passes gave Colorado a 14-10 lead at halftime.

Jackson returned the first punt of the game 54 yards to the Colorado 28, setting up Tim Duncan's 27-yard field goal.

Later in the quarter, Moschetti led the Buffaloes on an 11-play, 80-yard scoring drive, hitting Marcus Stiggers on a 14-yard scoring play.

After Colorado was pinned deep in its territory, Oklahoma took possession near midfield. Heupel completed 5-of-7, and Seth Littrell ran 2 yards for a touchdown and a 10-7 lead with 4:03 remaining in the half.

Colorado countered just 1:18 later when Green caught a short pass from Moschetti, then sprinted away from the defense for a 49-yard scoring play.

Colorado now has beaten Oklahoma five straight times and is 8-0-1 in the last nine meetings. It's the first time in their history that the Sooners have gone winless against any opponent over a nine-game span.