Renan Barao endured an early challenge from Michael McDonald before returning to business as usual.
Barao retained the Ultimate Fighting Championship interim bantamweight title with a fourth-round submission in the main event of UFC on Fuel 7 on Saturday in London.
It was the 31st straight fight without a loss for Barao. The only blemish during the streak was a no-contest in 2007 in Brazil.
McDonald was up to the task early. He went back-and-forth with the champion in the first two rounds.
Barao took control in the third, as he was more active in the striking game and bloodied McDonald’s nose with a flying knee. In the fourth, he secured side control on the challenger and locked in an arm-triangle choke that eventually ended the fight.
The interim champion made it clear after the fight that he wants to unify the belts in the 135-pound division.
“Dominick Cruz, I’m waiting for you,” Barao said through a translator. “Please come back.”
Cruz has not fought since October 2011 because of two anterior cruciate ligament tears.
Featherweight Cub Swanson won his fourth straight fight with a unanimous decision over Dustin Poirier. Swanson won all three rounds on two cards, but each round was tightly contested in a highly entertaining bout.
A light heavyweight bout between Jimi Manuwa and Cyrille Diabate was shaping up the same way until Diabate suffered what appeared to be a calf injury and was unable to continue after the first round, giving the victory to the hometown favorite.
Highly touted welterweight prospect Gunnar Nelson remained unbeaten with a unanimous decision over Jorge Santiago. Nelson took several huge shots just before the final bell but stayed on his feet.
James Te-Huna and Matt Riddle also won decisions on the main card.
On the undercard, Las Vegan Ulysses Gomez dropped to 0-2 in the UFC with a unanimous decision loss to Phil Harris in a flyweight bout.
Contact reporter Adam Hill at firstname.lastname@example.org or 702-224-5509. Follow him on Twitter: @adamhilllvrj.