Waco, Texas ? Bill Cosby gave a free concert at Floyd Casey Stadium a month ago in hopes of lifting the spirits of the Baylor campus.

As funny as he was, the jolly mood that night was nothing compared to the thrill the football team provided Saturday.

The Bears — winners of just four games in seven Big 12 Conference seasons and losers of 37 of their last 38 conference games — overcame a slow start to score five touchdowns in a span of 17:15 and beat two-time reigning Big 12 North champion Colorado, 42-30.

Aaron Karas threw three touchdown passes, Rashad Armstrong ran for 166 yards and two touchdowns, and the defense made several huge plays, including a fumble return for a score and a goal-line stop that prevented a go-ahead touchdown early in the fourth quarter.

It was a tremendous conference opener for new coach Guy Morriss, and a sweet moment for even-newer athletic director Ian McCaw, who watched Baylor (3-2 overall, 1-0 Big 12) play for the first time.

“The defense was fired up, the offense was fired up, and the crowd was fired up,” linebacker Justin Crooks said. “That’s what wins you games.”

The fired-up fans were peaceful after the game, swarming the middle of the field and jumping up and down.

Once players left, however, students noticed that while one goalpost was guarded by police, the other was surrounded only by volunteers. Several hundred fans stopped at that goal line, waited for reinforcements then charged into the end zone to chants of “Go! Go! Go!”

They toppled the uprights quickly, marched it around the field and out of the stadium.

There’s more to this celebration because joy has been scarce around Baylor lately.

The bad news began with the disappearance of basketball player Patrick Dennehy in mid-June. Dennehy was later found dead, a former teammate charged with murdering him. Then scandal swept the team, leading to the shameful resignation of the coach and athletic director and an investigation that could lead to stiff penalties from the NCAA.

Football hasn’t provided much relief, despite victories the two previous games over lowly SMU and Division I-AA Sam Houston State.

This one, though, came against a Colorado team ranked 17th a few weeks ago, making this among the most memorable victories in program history.

“There’s been so much frustration, the basketball situation is really sad — now we’ve got a good bead on what to do,” said Karas, who was 18-of-28 for 207 yards, with TDs of 8, 25 and 26 yards.

After a scoreless first quarter, running the Bears’ shutout streak against Colorado to nine straight periods, no one was thinking about dumping goalposts.

Everything changed a few minutes into the second quarter, when Baylor took over after a field goal put Colorado up, 3-0.

Karas led touchdown drives on four of the next five possessions, with the only non-score coming over the final minute of the first half. The defense contributed, too, with Jamaal Harper returning a fumble seven yards for the touchdown that put Baylor ahead 28-23, then a series of plays that made the lead stand up.

“The ball came right to me,” Harper said. “It bounced right into my hands.”

Two snaps later, CU quarterback Erik Greenberg fumbled a snap and Crooks recovered, leading to a three-yard touchdown by Armstrong and a 35-23 advantage. Then Baylor botched a punt, and Greenberg threw a 29-yard touchdown pass to Derek McCoy, getting Colorado (2-3, 0-1) within 35-30.

With 1:11 left in the third, it seemed like the Buffs’ pedigree might help them pull through — or that Baylor would return to its losing ways.

Instead, on the first play of the fourth quarter, Crooks helped throw Brian Calhoun for a 2-yard loss on fourth down from the one. Then the Bears drove it all 97 yards, with Armstrong scoring on a 55-yard run.

The Buffs benched Greenberg (16-of-29 for 346 yards and two TDs) and turned to Joel Klatt, who was superb in winning the first two games but hadn’t played since hurting his throwing shoulder in the third game.

His first pass became his first career interception.

“We are having confidence issues,” said Klatt, who finished 3-of-8 for 53 yards. “It’s hard to put a finger on what is going wrong, but we need to get our fire back. We prepared for Baylor, but they just outplayed us.”

Baylor has won three straight for the first time since going 3-0 in 1996, which came before its first Big 12 game.

The Buffaloes are on their first three-game skid since opening 0-4 in 2000. It doesn’t bode well for Colorado that every team that has lost to Baylor has had a losing record that year.