Eric “Drummer Boy” Molina, a 34-year-old Texan of quiet disposition and scant achievement, said before he stepped into the ring with Anthony Joshua here on Saturday night that he considered the WBC champion, Deontay Wilder – who stopped him in nine rounds – to be the best heavyweight in the world. As he sank towards the canvas here in round three, he was probably reassessing that judgment.

On a night that threatened to test boxing’s capacity to accommodate bad behaviour on the undercard, two gentleman heavyweights did their thing in the main event with all the quietude of a Sunday church service until Joshua exploded a venomous right on Molina’s chin in the third round. One more assault forced the American to spin into his own corner and he was taking further punishment when the referee called a merciful halt.

Molina more timid, even, than Charles Martin, the American from whom the Londoner ripped away the IBF title in April, and someway short in ability of another horizontal heavyweight from across the seas, Dominic Breazeale, who at least lasted into the seventh round two months later.

Now Joshua has to step up. There will be no more soft touches, no more learning fights with a world title belt around his waist. The promoter Eddie Hearn, grabbed to microphone to tell the 21,000 fans who had stayed after midnight: “I’d like now to bring Wladimir Klitschko to the ring, and I’m officially announcing the fight against Anthony Joshua at Wembley Stadium on 29 April.”

Klitschko asked the audience: “Do you want to see a big fight? Do you want to see two Olympic champions in there? You got it.” The reception was rapturous.

There was heavyweight royalty everywhere in the house: Klitschko and Tyson Fury – one waiting for a last hurrah with Joshua, the other maybe already having bid us adieu – as well as the ever-loved Frank Bruno. David Haye was here for Sky, his loud irritant, Tony Bellew, about 10 yards away for the BBC; they kept their distance. In America, Wilder manned the Showtime microphone.

Anthony Joshua and Wladimir Klitschko face each other down in the ring after Joshua’s victory. Photograph: Peter Byrne/PA

The champion, the owner of a perfect 18-0 record, all of them by stoppage, said of his public spar with Molina: “I just had to be patient.” It was a job of work safely completed – at odds with the excitement that followed.

Katie Taylor, the decorated Irish amateur in her second professional bout, had the experienced Brazilian lightweight Viviane Obenauf blinking and blowing. She put Obenauf down in the second and won comfortably on points over six rounds.

British boxing is enjoying a long and glittering run, with 12 world champions of varying status. Khalid Yafai became the latest – and Birmingham’s first – when he outclassed Luis Concepcion 120-108, 119-108, 117-112 to send the 31-year-old Panamanian home without the WBA super-fly belt he had surrendered on the scales on Friday. A neat left hook put the exasperated visitor over in the 10th for a quick count, and Yafai controlled nearly every exchange in the bout with crisp counters and superb movement.

Scott Quigg, a super-bantam champion until he lost to Carl Frampton in this ring in February, showed the benefit of moving up to featherweight, and stopped the difficult Jose Cayetono in the ninth round. The Mexican is another of those little man who have struggled to make weight, hitting the limit at the second attempt, yet Quigg looked bigger and stronger, finishing his comeback with a well-weighted shot to the chin in a neutral corner. His own jaw, broken in the Frampton fight, seemed to hold up nicely.

Just about any of the score of right-hand bombs Hosea Burton landed on Frank Buglioni’s chin from the first round to the 12th might have taken out his challenger for the British light-heavyweight title. Instead, Buglioni, rebuilding his career under the guidance of Chisora’s former trainer, Don Charles, soaked it up and, bleeding heavily from midway, rumbled through the storm to wreck the Mancunian’s unbeaten record and leave him battered on the ropes for a last-gasp stoppage, with 64 seconds left.