Calling Hrgovic's success merely psychological warfare would oversimplify and prove unjust, yet the 34-year-old managed to create an uneasy atmosphere during the buildup.

Throughout fight week Hrgovic repeatedly questioned Itauma's youth by calling him just a kid. As days passed Itauma grew visibly frustrated and finally lost control at the weigh-in by shoving his rival, prompting a slap in return from the Croatian.

Itauma takes pride in his thoughtful approach that stands out among heavyweights. He studies psychology and self-improvement books, speaks freely about sharpening his mindset, and appears to reflect on himself more than most 21-year-olds.

Still, deep reflection can slide into overthinking, a charge often made against Anthony Joshua in the later part of his career.

Whether the pre-fight comments mattered or not, Itauma's clear intention once the bell sounded was to finish matters quickly.

"Comments suggested he felt a world title required a knockout and that worried me," promoter Frank Warren said afterward.

Such thinking was logical after it had worked so well for Itauma before. Yet Hrgovic may have been underestimated by nearly everyone including the fighter, media, analysts, former boxers and bookmakers who made the Briton a strong favorite.

Hrgovic is an Olympic bronze medalist who went 12 tough rounds with the giant Zhilei Zhang and against Daniel Dubois, his only loss, he led on two scorecards before the bout ended due to cuts.

The fighter nicknamed El Animal understood pain, exhaustion and staying in fights when things went wrong. Itauma did not.

Itauma showed that many qualities which looked impressive against weaker opponents still worked against a genuine world-level heavyweight.

He proved he can absorb punches without any single blow exposing a weak chin. His hand speed troubled Hrgovic and made the Zagreb fighter appear slow.

With those strengths in view, what comes next?

"Stay determined. Keep confidence. Take some straightforward bouts for wins. Rebuild and learn from errors. Do not box like an amateur. Prepare for 12 rounds and manage your pace," was Hrgovic's advice.

Warren still sees Itauma as one of the most gifted talents he has met and points to two-time world champion Dubois as proof that heavyweights can recover well from painful defeats.

British boxing also knows the opposite outcome, where fighters such as David Price were once viewed as the next great heavyweight hope only for losses to damage an aura they never regained.

Audiences will now watch Itauma's every action, his breathing and how he handles fight distance. That openness may actually increase interest in him as a fighter.

The sense of flawless invincibility has disappeared. The young prospect has received instruction and observers will see what he takes from it.