Anthony Joshua expects Joseph Parker to bounce back after their contest in in Cardiff.
Joshua won the first heavyweight unification bout held on British soil as he saw off New Zealander Parker in front of a crowd approaching 80,000 at the Principality Stadium.
Joshua added the WBO belt to the WBA, IBO and IBF belts he already holds, but he was taken the distance for the first time in his professional career.
It was his 21st straight career victory, although previously unbeaten Parker delivered a battling display without seriously troubling Joshua.
Two judges awarded the fight to Joshua 118-110, with another scoring it 119-109, although regular interventions by Italian referee Giuseppe Quartarone did not help the fight develop any free-flowing nature.
Joshua will now head in the direction of a potential fight with WBC world champion Deontay Wilder, while Parker will have to regroup, get back in the gym and work back up the ladder to another world title fight.
"Joseph won't give up now - he's still young, competitive and I think we will definitely see Joseph Parker again," Joshua told reporters.
"Just on this evening, I was more focused, more disciplined and carried out the tactics and was the better man.
"Joseph played a massive part in this, his whole camp did and I'm honoured to share the ring with him. Credit to Parker, credit to Duco Events - they came, they stepped up and they tried, and they'll live to fight another day.
"I say my little prayer in the corner, I pray for success and I pray for his health and I pray he'll be safe once he leaves the ring. I made sure I spoke to Parker's mum before she left and say, 'Pat your son on the back, he's done well and he'll be back' - and that goes a long way."