Jake Paul scored a first-round TKO of Ryan Bourland on Saturday, stopping the professional boxer before Amanda Serrano’s title defence was cancelled at the last moment.

Paul, 27, quickly split his fellow American’s guard with repeated jabs, before adding right hands to the body and head to wobble Bourland, 35, against the ropes. Bourland, who entered Puerto Rico with a 17-2 pro record, scrambled around in a bid to recover, but he was eventually overwhelmed in the corner.

As Paul poured on punches, Bourland fell to his knees, and the referee stepped in to wave off the cruiserweight bout. With that, YouTube star Paul moved to 9-1 as a pro. The result in San Juan marked his second straight win against a pro boxer, with the “Problem Child” having knocked out Andre August in round one in December. Before Saturday (2 March), Bourland had not fought since September 2022.

Paul vs Bourland was set to be followed by a main event between Serrano and Nina Meinke, but the unified featherweight title fight was cancelled in a bizarre scene.

After Paul stopped Bourland, Meinke entered the ring in her fight gear, while Serrano arrived in sunglasses and a hoodie. A ring announcer revealed that the main event had been cancelled, and that the crowd would receive 100 per cent refunds. Champion Serrano, 35, said she had not been cleared to compete by doctors, owing to an eye injury.

“I came ready to fight, 100 per cent, I came to show my best and put on a great fight, but the doctor didn’t clear me – due to something to do with my eye,” said the tearful Puerto Rican.

“I wanted to fight in front of my people. I am so sorry from the bottom of my heart [...] I can barely see out of my eye.”

Paul, who promotes Serrano, added: “Amanda came to fight, put in a hard camp [but] she was failing some eye tests. Her cornea is exposed, you can’t risk losing your eyesight forever. I know she’s a warrior. This happened very last minute.”

Paul suggested that the issue arose 36 hours before the fight, which his promotional company – Most Valuable Promotions – will look to reorganise.

Serrano vs Meinke was scheduled for 12 three-minute rounds, in a rare move for women’s boxing, with the Puerto Rican’s unified belts on the line.

Serrano relinquished the WBC belt in December, when the council refused to sanction 12 three-minute rounds for her next bout. As a result, she lost her status as undisputed champion.