Oleksandr Usyk struck lucky to retain his world heavyweight titles in Egypt with a highly controversial 11th-round stoppage win against boxing novice Rico Verhoeven.

Verhoeven, in just his second professional boxing fight, was the clear aggressor for long spells, stunning generational great Usyk in a way nobody expected.

In a surprisingly tight contest, Ukrainian Usyk produced a late surge and landed a sharp left uppercut that sent the Dutchman to the canvas.

Verhoeven beat the count, but a follow-up flurry in the closing seconds of the round prompted the referee to step in and wave it off - a decision that looked extremely harsh on the challenger.

The scorecards at the time of the fight coming to a halt read 95-95, 95-95 and 96-94 to Verhoeven.

"This fight was hard. It was a good fight," Usyk said.

In a contest many expected to expose the gulf between elite boxing pedigree and crossover ambition, unbeaten Usyk looked uncharacteristically laboured.

The 39-year-old - a three-time undisputed champion who ruled at cruiserweight and heavyweight - found a way to win his 25th professional fight, but his opponent questioned the outcome.

Kickboxing legend Verhoeven, 37, described it as an "early stoppage" and called for a rematch but said it was up to Usyk.

"I wanted the referee to let me go out on my shield or let me go in the 12th. I felt we were pretty even on the scorecards," Verhoeven said.

Usyk's WBC title was on the line, with the bout also counting as a defence of his WBA 'super' belt - although Verhoeven would not have been eligible to win that version of the title in the event of an upset.

The IBF granted permission for the contest but did not sanction its belt. (BBC)