WEMBLEY, London — Not long after the bell sounds to begin Anthony Joshua’s rematch against Andy Ruiz Jr., fans, who are packed four-deep at the bar and fill every corner at a fan zone in London on Saturday night, are growing in anticipation to see who will strike first.

Jab after jab, Joshua has been maneuvering his way around the ring. Then the Brit lands the first meaningful shot of the night, a hard and fast right hand that cut Ruiz above his left eye. Fans roar with relief. The end of the first round, which Joshua undoubtedly won, is greeted with a chorus of his signature chant, the belting tune of the Whites Stripes’ 2003 single “Seven Nations Army”.

In the shadows of the Wembley arch — where he had delivered perhaps the best fight of his career when he rose from the canvas to achieve an 11th round knockout of Wladimir Klitchsko — big screens at the fan zone show Joshua box his way to a masterful points victory over Ruiz to become a two-time unified heavyweight champion.

Fans have packed out the 2,500 capacity arena in Wembley, all vying to see the former heavyweight champion prove that his shocking seventh round TKO loss to Ruiz on June 1 was just a fluke, that it was all due to a powerful left hook that Ruiz landed early in the fight that showed the anything-can-happen nature of heavyweight boxing.

Fans of the Watford-born fighter have been resentful of that last fight ever since its conclusion, failing to land on a reasonable excuse as to why Joshua, undefeated with 21 knockouts in 22 fights at the time, could have lost his four title belts to the significantly physically inferior Ruiz. But their belief never waned — the vast majority in attendance on Saturday let it be known throughout that Joshua was expected to win — and can now justifiably mark down Ruiz’s special night in June as just a blip in the glowing career of Joshua.

The arena in Wembley drowned in boos before Ruiz’s ring walk. Just a single fan, who lives nearby in South Harrow, looks to be obviously supporting Ruiz, donning a sombrero and poncho while shaking maracas for most of the fight in support of the reigning champion’s Mexican descent. He is sitting on a table near the back of the hall that limited most of the jibes from a pro-Joshua crowd, and will later insist that he received “a few looks”.

The first round had shown that Joshua is quicker than he had been in the first fight and proved again that he could be effective at range.

Joshua wins the second and third rounds. He keeps punishing Ruiz with his jab, who is pursuing but cannot get into range to land a heavy blow to send Joshua on the back foot, just as he had in their first fight.

For almost the remainder of the fight, round after round floats by with a measured atmosphere that reflects the bout on screen. Joshua is boxing a polished fight, shutting down Ruiz in what is becoming a tactical masterpiece. There are just a few patrons throwing punches in the air and demanding for Joshua to press for a knockout, and chanting has mostly ceased by now. There are not many wild punches capable of whipping up a frenzy.

The chanting of Joshua’s name finally resurfaces moments before the final round of the bout. A powerful right hook from Ruiz, seen beforehand as maybe his best chance to beat Joshua, now looks to have little chance of landing. The party is just beginning.

Beer showers the arena at the final bell as plastic cups fly into the air and inflatable clappers that had been handed out by organisers are being thrown around. These fans had remained loyal to Joshua, their champion, whether he was in possession of the heavyweight belts or not, and have been duly repaid.

One of the security guards at the arena, Julius Francis, was a boxer himself years ago, his career peaking with a punishing knockout loss to Mike Tyson inside of four minutes at the Manchester Arena in 2000. He is sure that Joshua has consolidated his fan base and that they would be back again next time.

“The fans would always come,” Francis says. “When Joshua fights at Wembley, he’s fighting in his backyard with 90,000 people packed in.

“Fans will keep going back and fill it again off the back of that fight.”

Joshua’s masterclass has restored some of the aura that has followed him for most of his professional career and there is a sense that, despite having already maintained a loyal band of support, the Brit has won back any fans that he may have lost in June.

The Ruiz fan in the crowd, the one donning all the Mexican memorabilia for most of the night, had removed his poncho and head gear by the latter rounds.

“I put the Sombrero down,” he says. “I got a sense of the crowd. Joshua put on a masterclass. I think that was the best he’s been since he beat Klitschko.

“British boxing fans are different to everyone else, we want a fighter. Joshua gave us that tonight.

“I’ll go watch him fight again if he keeps doing that.”