WITH TYSON Fury's surprising dethronement of long-reigning heavyweight champion Wladimir Klitschko on Nov. 28, the big-boy division that often has been described as the engine that drives professional boxing is suddenly like a train whose cars have been uncoupled and switched onto any number of different tracks with destinations of . . . well, who knows where?

One of those runaway locomotives rumbles through Verona, N.Y., on Saturday night, where North Philadelphia's Bryant "By-By" Jennings (19-1, 10 KOs) takes on Cuban defector Luis Ortiz (23-0, 20 KOs) in the scheduled 12-round main event of an HBO "Boxing After Dark" telecast originating from the Turning Stone Resort and Casino.

With the abrupt ending of Klitschko's championship tenure, which included 19 defenses - the second-longest in heavyweight boxing history behind the legendary Joe Louis' 13-plus years and 26 defenses, Fury, an Englishman of Irish descent, becomes the new main man.

Fury now holds Klitschko's WBA "super" title and the WBO, IBO, and The Ring and lineal titles, But, the IBF recently stripped Fury of its title for opting for an immediate rematch with Klitschko instead of committing to his mandatory against Ukraine's Vyacheslav Glazkov (22-0-1). Deontay Wilder (35-0, 34 KOs), of Tuscaloosa, Ala., is the WBC champion, set for a Jan. 16 defense against Poland's Artur Szpilka (20-1, 15 KOs) at the Barclays Center in Brooklyn, N.Y.

The winner of Saturday's bout - Ortiz, 36, is defending his WBA "interim" heavyweight title, whatever that is, against the 31-year-old Bryant - moves to the front of the WBA line for a shot at the survivor of Fury-Klitschko II. It's a Gordian knot that might take some time to completely untangle, but Jennings, who lost a unanimous decision to Klitschko on April 25 in Madison Square Garden, is eager to get a second crack at his sport's ultimate prize.

"That 'L' to Klitschko wasn't a loss," Jennings said. "It was a learn."

At first glance, there wouldn't appear to be much Jennings and Ortiz have in common. Jennings, a former three-sport star at Benjamin Franklin High, came to boxing late, at 24, logging just 17 amateur bouts (he was 13-4) before turning pro in 2010. Ortiz, a southpaw, was a reported 343-19 as an amateur, winning the Cuban heavyweight title in 2006 and 2005 Pan American Games championship before he defected, arriving in Miami and also turning pro in 2010.

And then there is the matter of what these two very different individuals, each of whom is predicting a knockout victory, put into their bodies. Like most fighters, Ortiz - who tested positive for Nandrolone, an anabolic steroid in 2014, which damaged his reputation - consumes lots of beef, chicken and pork; since 2013 Jennings, who appears almost professorial outside the ring with his black-frame glasses, has adhered to a strict vegetarian diet.

"I fought Szpilka on it," he said of his carefully considered food choices. "I fought (Mike) Perez on it. I fought Klitschko on it. Everything was fine."

Should Jennings eventually win a version of the heavyweight title, he would become the first Philadelphian to do so since Tim Witherspoon in 1986. Ortiz hopes to become the first Cuban to win a heavyweight title, something the legendary likes of Teofilo Stevenson and Felix Savon, each of whom won three Olympic gold medals, never got the chance to do because they never turned pro.

"I am 100 percent sure I will demonstrate to the world that a Cuban will be heavyweight champion," Ortiz said. "I'm going to make a statement (against Bryant)."