“I would love to have a very, very, very long speech,” Wladimir Klitschko said at a news conference before his fight with IBF champion Anthony Joshua. (Daniel Leal-Olivas/AFP/Getty Images)

Wladimir Klitschko’s eyes lit up as he looked around the massive atrium and saw hundreds of people lining the staircases and railings, craning their necks for a glimpse. The 41-year-old future boxing Hall of Famer was about to speak Thursday at a news conference in advance of his IBF heavyweight championship bout Saturday against British champ Anthony Joshua. It was clear he was thoroughly enjoying the moment.

“Good day, ladies and gentlemen,” Klitschko said with an engaging smile. “It’s an amazing crowd here. And I would love to have a very, very, very long speech.”

The audience laughed at Klitschko’s joke, but it’s possible that there was some truth hidden beneath the surface. Watching Klitschko’s gleeful byplay with the fans, it is obvious he does not want his time in the spotlight to end.

Why else would Klitschko, a two-time heavyweight champion with a sterling record of 64-4 and 53 knockouts, fight an opponent as dangerous as Joshua — before a partisan sellout crowd of 90,000 at Wembley Stadium — at this late stage of his career?

At 18-0 with all of his victories coming by knockout, Joshua, 27, is one of the most exciting young heavyweights to come along in some time. He dispatches opponents with Tyson-like ease, and he has a similarly electrifying presence. Only two of his foes have made it past the third round (each was knocked out in the seventh).

For all his promise, Joshua would be lucky to one day equal Klitschko’s accomplishments. Joshua holds the IBF belt, but Klitschko defended it 18 times over nine years until he was upset by Tyson Fury in .November 2015.

Most would consider it a blow to their pride to be considered the B-side in a match against a fighter with a lesser résumé. Not Klitschko. He accepted the assignment with gusto.

“Is it a degradation that I’m actually a challenger and underdog in this fight after 27 years in the sport?” Klitschko said. “I don’t think so. I think it’s great.”

In part because of the dearth of quality opposition, and in part for fighting in a style sometimes dismissed as boring, Klitschko’s historic reign atop the heavyweight division was largely met with shrugs, at least in the United States. But Tom Loeffler, the managing director of K2 Promotions, which promotes Klitschko, believes that could change Saturday with a career-defining victory at a late age.

“He’s got such a great legacy. Such a domination of the heavyweight division,” Loeffler said. “But at the same time, with all those wins, this is the biggest event of his career.”

The fight is arguably the most anticipated bout in boxing’s glamour division since the 2002 showdown between Lennox Lewis and Mike Tyson. As with that megafight, this bout has brought HBO and Showtime, the bitter premium cable rivals, together on a boxing telecast for only the third time in their history. Showtime will air live coverage beginning at 4:15 p.m. Eastern time, and HBO will air the fight on tape delay at 10:45 p.m.

Executives from both outlets credited the other side for coming together on the unusual arrangement.

“I think everyone wanted to work in the service of the fans and the sport,” said Peter Nelson, executive president of HBO Sports. “This is a signal that the sport is moving in the right direction.”

British boxing impresario Eddie Hearn, the group managing director of Matchroom Sport and the fight’s lead promoter, admitted the talks grew heated at times.

“It’s the hardest deal I’ve ever had to do in boxing,” said Hearn, a licensed promoter since 2011. He added, “Listen, they don’t like each other. Everyone knows that.”

In the end, Stephen Espinoza, executive vice president of Showtime Sports, believes the sides were brought together by a sense of duty to a sport that too often has seen major deals fall apart over petty disputes.

“We wouldn’t have gone to this effort, and we wouldn’t have made the concessions that we made if it weren’t an historic fight,” Espinoza said.

Whether or not it is historic, the bout is expected to attract the largest crowd for a boxing-only event since 1993. (Two fights in Russia staged jointly with a popular motorbike show have drawn larger crowds.)

Paulie Malignaggi, a former welterweight world champion who will call the bout for Showtime on Saturday, believes the massive crowd is what compelled Klitschko to take such a risky assignment. Malignaggi can relate. At age 36, the boxing analyst continued to fight until last month before announcing his retirement after a loss. It was the attention that kept Malignaggi going.

“Your ego still wants to feel that adulation,” Malignaggi said. “Your ego still wants to be part of big moments. Your name in lights. Be cheered as you walk in.”

Malignaggi’s assessment seemed to be affirmed by Klitschko’s jovial demeanor at Thursday’s new conference. Even as his remarks drew to a close, it was clear Klitschko had no desire to exit the stage.

“Thank you very much for your attention,” he said, sitting back in his chair, basking in the crowd’s applause.