At UFC 141, Alistair Overeem successfully made his UFC debut against Brock Lesnar with a first round TKO. The stoppage was set up with a kick to Lesnar's liver. Overeem then swarmed Lesnar forcing referee Mario Yamasaki to call the fight halfway through the first round. The stoppage earned Alistair Overeem a shot at Junior Dos Santos' UFC heavyweight title when the champion returns from his knee injury.
Following the loss Brock Lesnar retired in the cage stating that even had he been successful he still was planning on retiring following his guaranteed title fight. It's a historic fight for the UFC who just saw their biggest PPV draw retire. From Brent Brookhouse's play by play of the action:
Brock Lesnar vs. Alistair Overeem - Round 1 - Leg kick from Lesnar early, and another and then a jab. Looping right just misses. Lesnar drops for a single and can't get it. Lesnar has cut Overeem above his eye. Big knee to the body by Overeem. Another hard knee. Those body shots are hurting him badly. Another knee and he's still hurt. Liver kick by Overeem and Lesnar takes a few steps back and takes a knee against the cage, Overeem unloading with punches and that'll do it. Alistair Overeem wins by TKO (liver kick and punches), 2:26 round 1.