Heavyweight Wladimir Klitschko (64-4, 53 KO) has opted to exercise the rematch clause in his contract with Tyson Fury and fight the world heavyweight champion for a second time.

Fury (25-0, 18 KO) defeated Klitschko by unanimous decision last Saturday in Germany, claiming the WBO, WBA and IBF heavyweight titles in the process. It was Klitschko’s first loss since 2004, ending a streak of 18 consecutive title defenses as the 6-foot-9 Brit became the first U.K. heavyweight champion since David Haye and the first lineal heavyweight champion since Lennox Lewis’ retirement in 2004.

Klitschko reflected on the loss and hinted at a return to the ring on Wednesday.

“I was really frustrated after the fight but after some short nights I now know that I want to show that I am much better than my performance on Saturday,” Klitschko told reporters at his home in Hamburg. “I couldn’t show my full potential at any time. This is what I want to change in the rematch—and I will. Failure is not an option.”

From the moment the fight ended, Fury seemed intent on giving the former longtime champion a crack at winning his belts back, shrugging off the possibility of fighting anybody else. A rematch means rising heavyweight contender Deontay Wilder will have to wait for the likely winner.

"I’d like to come to Germany again to fight Wlad," Fury said in the post-fight press conference. "Wladimir Klitschko was the number one in the division. Probably the pound-for-pound king."

Anyone who wants to fight Fury is “going to have to wait, because Wladimir Klitschko has a round two ... ding ding ding,” the champion added.

The rematch is to take place next year with the date and venue yet to be determined.