Johnny Fisher was taken to hospital after his shock split-decision win over Dave Allen on Saturday.
Romford's popular Fisher was looking for a breakout performance on the undercard of the Oleksandr Usyk vs Tyson Fury rematch in Riyadh, but instead found himself dropped by Allen in the fifth round of their bout.
The English fighter went on to take the vacant WBA Inter-Continental heavyweight title in contentious fashion and after the fight, Fisher's dad John posted on Instagram that Johnny had been taken to hospital for a brain scan.
"Well done @whiterhino_21 a true warrior and a man who we are proud to know. Johnny got the rub of the green tonight in a brutal encounter. We are currently in hospital for a brain scan to make sure all OK," he wrote on his Instagram story.
"Thank everyone of you tonight for supporting both him and Dave. Proud of my boy."
A fast start from Fisher in the fight, looking the stronger in the opening round, did not dishearten Allen.
The veteran from Doncaster turned the momentum his way, rocking Fisher with tremendous uppercuts, backing them up sometimes with his right hook and at another moment with a stunning left.
Fisher kept his feet under him in the second half of the fight but Allen continued to stun him with full-blooded shots.
Allen warmed to his work as he harried Fisher, seeming to take the lead. Cunning, Allen suddenly waited, let Fisher cover up, saw the opening and heaved a right hook into it.
Fisher had lost his shape and form in the ninth round. He looked ragged and disorganised, his legs stiff and sluggish, while Allen beckoned him in.
Full of heart, living up to his nickname, Fisher bulled into Allen in the 10th. A booming cross down the middle caught Allen flush. But the Doncaster man would not let himself fall at the final hurdle.
The judges however ruled against him. One official scored 96-93 for Allen but the other two both had it 95-94 for Fisher, much to the Doncaster man's consternation.
"Everyone ringside said that I'd won. I thought I won my first title as a pro," Allen told Sky Sports afterwards.
"I'd thought tonight was gonna be a horror show but by the final bell, I thought I might have done enough, but it doesn't matter what I think.
"I've digested quickly. I'm nearly 33, he's a young kid. I'm really happy for him.
"I just take and go on to the next one. We're going to fight another day."
Asked whether there could be a rematch on the cards, Allen added: "I don't think so. I don't think it's the right fight for him.
"That's probably not for me to worry about, but I do. He's a lovely kid; I think we should have a fight in between, and then maybe do it again."
Britain's Moses Itauma is still only a teenager. But the 19-year-old demonstrated why he is one of the most highly-regarded prospects in world boxing with a first-round demolition of Demsey McKean.
The Australian had acquitted himself well at a good level against Filip Hrgovic. But he could not contend with Itauma.
The Briton dropped him cleanly early on and then pounced. His left cross landed with brutal force to put McKean down and out of the fight.
Rhys Edwards stepped in to replace Dennis McCann and fight Tokyo Olympian Peter McGrail on four days' notice, arriving in Riyadh just two days before the fight.
The Welshman did give McGrail problems to negotiate, especially after their heads clashed together and left the Liverpudlian cut alongside his right eye.
McGrail, a southpaw, moved nimbly up close, smacking hooks into the body and working round a lead hook. He found the measure of his opponent but it was no easy fight.
Edwards still let hard hits thud in off his right and left hands, landing with an impact that McGrail must have felt.
Into the ninth round, the Welshman was still firing back after McGrail whipped in flashy punches.
Despite his short notice assignment, Edwards didn't fade. In the 10th and final round McGrail had to tag him back with a fast one-two but the Welshman knocked him back with an uppercut. McGrail though took a close but unanimous decision, winning 96-95 and 96-94 twice.
An England versus Scotland clash saw Morecombe's Isaac Lowe take on Lee McGregor, the former European champion from Edinburgh.
They began frenetically but despite Lowe's efforts, McGregor managed to place his left hooks and tie up his opponent.
As McGregor chalked up rounds, Lowe remained full of endeavour. He forced his way on to the front foot but struggled to put a dent in McGregor.
The bad blood between them became evident in the seventh round when they struck each other on the break.
The fight grew gritty and untidy, with Lowe the more frustrated, even kicking his own stool at one point. His mouthpiece fell out too often and he had a point taken off in the ninth and 10th rounds, sealing a unanimous points win for McGregor, 96-92 and 97-91 twice.
A star performer on the undercard was Ukrainian super-welterweight Serhii Bohachuk, who dominated Ishmael Davis in a final eliminator for the WBC super-welterweight title.
He dropped the Briton in the second round, a right hook setting up a pinpoint left hook to the chin.
Leeds' Davis had come in to replace Israil Madrimov at short notice. Despite his gutsy efforts, after being badly marked up by the sharp, dangerous punching of Bohachuk, he had to be saved from his own bravery after six rounds.
Ukrainian heavyweight Andrii Novytskyi got the show underway, beating Mexico's Edgar Ramirez in a sedate 10-rounder, taking a unanimous decision 100-90 twice and 98-92.
Tall southpaw light-heavyweight Daniel Lapin chalked up another 10-round unanimous points win for Ukraine, beating Dylan Colin 100-90 and 99-91 twice.
Repeats of Oleksandr Usyk and Tyson Fury's huge heavyweight rematch will be shown at 8am and 6pm on Sunday December 22 on Sky Sports Box Office. Book Usyk vs Fury 2 repeats now!