updated 11:42 p.m. ET Nov. 21, 2009

AUSTIN, Texas - Colt McCoy fired the cannon. He banged the big drum.

Then he left the field to chants of “Colt for Heisman!”

There’s still plenty of work to do for the quarterback of No. 3 Texas, but for this one last night in front of the home crowd, he was going to have some fun.

McCoy passed for 396 yards and four touchdowns, earning his NCAA record 43rd career victory as a starter in a 51-20 win over Kansas and embattled Jayhawks coach Mark Mangino that wrapped up the Longhorns’ first Big 12 South title since 2005.

“I always love winning,” McCoy said. “I’m just so thankful. It’s really special.”

McCoy, playing his final home game, improved to 43-7 in his career, breaking the record he shared with former Georgia quarterback David Greene (2001-2004).

Texas (11-0, 7-0) still have a Thanksgiving game at rival Texas A&M left to play before the Big 12 championship on Dec. 5 against Nebraska. Win those two, then it’s off to Pasadena, Calif., for the BCS national championship game for McCoy and the ’Horns.

“It’s been a long time coming,” senior defensive end Sergio Kindle said. “There’s been a lot of hard work put into getting where we are now. It’s not over.”

McCoy threw touchdown passes to Jordan Shipley and Malcolm Williams and two to James Kirkendoll.

Kansas (5-6, 1-6) dropped its sixth straight, adding to a miserable week and season for Mangino. University officials are investigating Mangino over allegations of emotional and verbal abuse of players, fueling speculation he may be fired.

The defeat only compounds Mangino’s mounting troubles. The 2007 coach of the year is 50-47 in his eighth season. He could still lead the Jayhawks to a third straight bowl game for the first time in school history with a win over Missouri next week.

Mangino said he had no doubt he’ll coach against the Tigers.

“I’m ready to go (against Missouri), but you asked the wrong person that question,” Mangino said.

Asked about the turmoil of the last week, Mangino talked about Jayhawks player D.J. Marshall, who he said started chemotherapy for cancer.

“That’s called a bad week. I’ve had a great week,” Mangino said.

McCoy’s big night and two more games to shine on national television could give his Heisman Trophy hopes a big late-season boost. He has 23 touchdown passes and just missed 400 yards passing for the second time in three games.

“I don’t think we could have scripted it any better,” coach Mack Brown said. “He is in here for a big finish and he was sending that message tonight.”

Unlike other games when Texas was winning big and McCoy watched the fourth quarter from the sideline, he stayed in against Kansas until late to say a final goodbye to the home fans.

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With about six minutes left, the Texas-record crowd of 101,357 chanted “Colt! Colt!” McCoy hugged Brown, saluted the fans and pointed at the sky before jogging into the huddle.

Texas then called a timeout and he and Shipley walked off the field together to a thunderous ovation. The roommates have connected for 28 touchdowns.

“They are probably one of the best combinations in college football history,” Kirkendoll said.

After the game, most of the crowd stayed to watch as McCoy and Texas’ other seniors high-fived fans in the front row. The players went to the corner of the end zone and fired the cannon used to punctuate Longhorns touchdowns. Then McCoy pounded three times on the “Big Bertha” bass drum before leaving the field.

“I’ve never hit the drum. I’ve never shot the cannon. It was pretty sweet,” McCoy said. “That was the perfect time to do it.”

Special feature Texas gunslinger Check out quarterback Colt McCoy in action. NBCSports.com

McCoy was a redshirt freshman in 2005 when Vince Young led Texas to the Big 12 title and its first undisputed national championship in 36 years with a victory in the Rose Bowl. McCoy’s first win came on Sept. 2, 2006, when he threw a 60-yard touchdown pass on the second throw of his career.

Back then, the Longhorns went to a no-huddle offense in part to keep him from getting intimidated by the seniors on the offensive line.

Texas still runs the no-huddle to keep up the pressure on defenses. Saturday night, McCoy’s fifth pass was a 41-yard scoring strike to Kirkendoll when he lofted the ball behind two defenders as the receiver streaked down the sideline.

Kansas put up some of the best numbers of the season against the nation’s top-rated defense. Jayhawks quarterback Todd Reesing passed for 256 yards. Dezmon Briscoe had a 98-yard kickoff return for a touchdown.

But this was McCoy’s night.

He connected with Shipley for a score right after he got popped hard on a scramble. The 68-yard touchdown pass to Malcolm Williams came on the first play after Kansas had cut Texas’ lead to 27-13.

McCoy did just about everything in this one. He rushed for 29 yards and even punted a pooch kick in the third quarter.

“It was definitely enjoyable,” McCoy said. “A memorable one.”

Also on NBCSports.com Rosenthal: Saints win with aggressive ‘ambush’ Trash Talk: How will Manning rebound from loss? NBA: ProBasketballTalk is here! Check out new blog NCAA BK: Who's in, who's out? Updated bracket projections Twitter: Follow us @nbc_sports

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