The judges scored the bout 29-28, 29-28, 28-29.
"That's one tough dude, man," Hendricks said. "I hit him with everything I got. Everything I could. Hat's off to that dude. He's a real fighter."
Hendricks best moment came in the third when he clearly wobbled Koscheck with a series of left hands. But his worst moment came in the same round, when Koscheck took him down and worked from the top for the final two minutes.
It was that kind of fight, with many momentum turns throughout.
The first round was close, featuring Koscheck walking down Hendricks for long stretches. Hendricks seemed comfortable fighting with his back against the fence, but it opened up some holes for Koscheck to fire off and land.
Hendricks did land the round's only takedown two minutes in, but he couldn't hold him there as Koscheck popped up quickly.
The second was quite similar, with both men looking to land their big punch -- for Koscheck and overhand left, for Hendricks a left hook -- with little success. That left lots of jockeying for position against the fence, with both men trying to show off their wrestling pedigrees. Hendricks scored two in the round but again was able to do little with them.
Hendricks had his best striking success in the third, rocking Koscheck with a looping left. A series of follow-up strikes had Koscheck moving backwards until he could initiate a clinch for recovery. That ended up being a wise decision, because moments later, Koscheck took him down and held him to the mat for the final two minutes. Though his strikes from the top weren't overwhelming, it seemed like it could be enough to let Koscheck steal the fight. But it was not to be.
Instead, the welterweight division has a new contender.
"Give me that title," Hendricks said. "Give me it. I want to bring it home to Texas."
Hendricks' fourth straight win made him 13-1 overall. Koscheck fell to 17-6.