Cardiff - Anthony Joshua called for a heavyweight unification fight with Deontay Wilder, saying it was "not time to sit back and enjoy the ride", after beating Joseph Parker in Cardiff on Saturday.
Joshua added Parker's World Boxing Organisation heavyweight title to his International Boxing Federation and World Boxing Association belts with a unanimous points decision over the New Zealander after being taken to 12 rounds for the first time in his unbeaten 21-fight professional career.
Now the pressure will build for a unification bout with the United States' Wilder, the World Boxing Council heavyweight champion.
"I want Wilder... Get him in the ring and I'll knock him spark out," Britain's Joshua said in the ring immediately after judges had scored the fight 118-110, 118-110, 119-109 in his favour.
But the London 2012 Olympic champion was in more considered mood at the post-fight press conference.
"2018 was always a time to capture all the belts," said Joshua, flanked by promoter Eddie Hearn and trainer Rob McCracken. "We are one away now.
"In my eyes, it's not time to sit back and enjoy the ride."
The unbeaten Wilder took to Twitter after Saturday's contest in front of a 78,000 capacity crowd at the Principality Stadium to insist he was "the baddest man in the world, the baddest man on the planet, and that's fact".
Joshua refused to rise to Wilder's comments, including a previous remark when the American said he wanted a "body" on his record.
"I'm not into the business of hype, hype, talk, talk. I'd love to maybe go to America with Eddie and Rob and look at the landscape and see how serious they are, and deal with this behind closed doors."
Hearn added: "I think it has to happen in 2018 otherwise we are going to hit some major problems with the politics and the mandatories (mandatory defences of the various belts).
"If they (Wilder's camp) stepped up and were actually serious about the fight, and serious about a deal we are more than fair to offer them, it could happen next.
"But they are so erratic and unpredictable, I don't know what to believe."
Meanwhile a gracious Parker had no complaints after his first defeat in 25 bouts as a professional.
"We enjoyed being here, he (Joshua) deserved to win. "We're still young, we'll be back, we'll be champion again," added the 26-year-old.
Parker and his camp were frustrated by the way Italian referee Giuseppe Quartarone repeatedly intervened to stop any close-quarter work developing between the two boxers.
They questioned the Italian's suitability for taking charge of such a big fight given what they said was his poor grasp of English.
"We're not blaming the ref (for the defeat) but he couldn't really speak English," said Parker. "I wanted to work on the inside more."
Parker's trainer, Kevin Barry, agreed. "Obviously when one guy (Parker) has got a 76-inch reach and the other guy has got 84 or 85, it's important when we do close the distance so that we are able to work," he said.
"Unfortunately for us, the referee just didn't allow us to do that.
"I knew he was from Italy but I obviously expected we would have a guy who could communicate with the two participants fighting."
Butt Joshua's trainer McCracken countered: "When he explained the rules for two minutes he spoke English."
Barry, however, would not blame the referee for Parker's defeat. "I was quite impressed with a lot of things Joshua did, he held his hands better and was quite hard to hit," Barry said.
Meanwhile David Higgins, Parker's promoter, said there was plenty more to come from his man.
"I saw the look in Joseph's eyes, this has made him hungrier," Higgins insisted.