With an arsenal of crushing knees and body kicks, Alistair Overeem made an impressive UFC debut, earning a heavyweight title shot and putting an end to the brief but scintillating career of former UFC champ Brock Lesnar.

From the opening bell, Lesnar, who has struggled against two bouts of diverticulitis, appeared uneasy at striking range, but would fare no better at close distance. Showing little concern for Lesnar's striking prowess, Overeem fairly marched forward into the clinch, where time and again his knees left Lesnar nearly doubled over along the fence. A roundhouse to the liver, followed by some perfunctory punches, forced Lesnar down for good. Lesnar announced his retirement during his post-fight interview with Joe Rogan...

My hat's off to Alistair Overeem. I want to take my hat off to all my training partners, my wife, my family. I've had a really difficult couple of years with my disease and uh...I'm gonna officially say that tonight will be the last time you'll see me in the octagon.

[...]

I wanna thank everybody. I wanna thank the Fertitas, Dana White. Brock Lesnar is officially retired. I promised my wife and my kids...if I won this fight I would get a title shot and that would have been my last one but if I lost tonight...everyone you've been great. Alistair, it's been a pleasure.

With this win, Overeem earns his first ever victory in the UFC and extends his undefeated streak to twelve. The one-time Strikeforce champion hasn't been beaten since a September, 2007 knockout at the hands of Sergei Kharitonov.

Lesnar retires with a career record of 5-3-0. Lesnar fought and won the heavyweight title in only the fourth fight of his career, and with subsequent victories over Frank Mir and Shane Carwin he became not only a fixture of a booming UFC, but the top-ranked heavyweight in the world.