 In January 2010 , Lesnar announced on ESPN 's SportsCenter that he was scheduled to make a return to the UFC in the summer . A match between Frank Mir and Shane Carwin took place on March 27 at UFC 111 to determine the Interim Heavyweight Champion , and Lesnar 's next opponent . Shane Carwin defeated Mir via knockout in the first round , becoming the new Interim Champion . After the fight , Lesnar came into the ring and stated , " It was a good fight but he 's wearing a belt that 's a make @-@ believe belt . I 've got the real championship belt " . Lesnar faced Carwin at UFC 116 to unify the heavyweight titles . Early in the first round , Carwin knocked Lesnar down with punch , gave him a cut above his left eye , and used a ground and pound attack the rest of the round . In the next round , Lesnar was able to take Carwin down , attain a full mount , then move into side @-@ control and finish the fight with an arm triangle choke . With the victory , Lesnar became the Undisputed UFC Heavyweight Champion , earning his first Submission of the Night and giving Carwin his first loss . The win also tied a UFC record for most consecutive successful Heavyweight Championship defenses . 
