After five Philadelphia Fusion players took the stage in Burbank, Calif., for their Overwatch League video game match with the Boston Uprising, many of the 500 hometown fans at Revolutions Bowl in Northern Liberties were wondering why the Fusion was missing a player.

Then the horn-heavy sounds of "Gonna Fly Now" radiated from the tunnel. A marching band emerged, followed by the sixth man, Simon "snillo" Ekström, wearing a Rocky Balboa sweatshirt and sweatpants.

Ekström's entrance was a hit for the fans back in Philadelphia, who had gathered for a watch party hosted by the professional video gaming team. The event attracted more than 500 people, and more than 100 fans were outside waiting when the doors opened at 7 p.m. — two hours before the shooter video game matchup began.

Hugely popular with millennials, e-sports are growing as traditional sports audiences have fragmented and aged, executives say. There are some 35 million Overwatch video gamers, with 300,000 to 500,000 in the Philadelphia region.

Teams reportedly paid $20 million to purchase slots in the Overwatch League, which includes owners and investors from the NFL, MLB, and the NBA. Players make a minimum of $50,000 a year, though the best command more.

The league hopes to make money for owners through advertising, ticketing, and broadcast rights revenues, with teams receiving an equal share of all league-wide net revenues, according to Overwatch publisher Activision Blizzard. Some teams have patches on their jerseys with sponsors like Jack in the Box restaurants, though the Fusion are still working on finding the right one.

"We've been blown away with the work that the league has done from the business side," said Fusion President Tucker Roberts, referring to new league partnerships with brands like T-Mobile, Sour Patch Kids, and Toyota. "And we're starting to see a lot more traction on team deals."

Owned by Comcast Spectacor, the Fusion play in the Flyers' orange, white, and black colors, and are one of 12 teams that try to kill each other and achieve an objective — like King of the Hill — before a live crowd and hundreds of thousands of viewers online.

The first season is divided into four five-week-long stages​.

A few weeks back, the Fusion faced the New York Excelsior in a best-of-five stage 2 series with $100,000 on the line. They had a 2-0 lead but ending up losing by 3-2. Viewership peaked at 216,000 on the English language stream, which doesn't count the Korean, French, and Chinese audiences.

The Fusion have a basic geography problem. While its games will be played in Burbank, Calif., until sometime in 2019, it needs to build a sustaining fan base here. The team will finally visit hometown fans in May, but for now a team cameraman recorded questions for the players in Burbank to answer.

"I literally said, 'How do you teach gaming to a generation that didn't grow up with gaming?'" said Susan Stein, CEO of the medical communications firm Connexion Healthcare in Newtown, Bucks County, who came with her husband because she wants to share in the passions of her college-age son. "It's a really amazing way to connect with him. I've learned so much about him through this."

Denzel Echevarria, 25, came with friends to watch his favorite Fusion player, Jae-hyeok "Carpe" Lee.

When the Fusion won during their first watch party at Wahoo's Taco, "I literally bought a jersey on the spot," Echevarria said. "I watch every game that I can from home."

"This is my main sport," added Ross Magargee, 19, a freshman at Harrisburg University of Science and Technology. "I've been really excited since they first announced it."

Magargee came with a few dozen classmates from Harrisburg, which announced its partnership with the Fusion Thursday night. This partnership will include programs for Harrisburg students like summer camps and job opportunities, said Chad Smeltz, the e-sports program director at Harrisburg University.

The opening for stage 3 didn't go so well for the Fusion. Down 2-1 with one last chance to force the game into overtime, Carpe showed why he's a fan favorite by killing three competitors at once and helping the Fusion tie it up. The crowd at Revolutions erupted. But a Villanova-like ending was not to be. The Boston Uprising, owned by Robert Kraft of the New England Patriots, won the final game convincingly, and handed the Fusion their eighth loss. The Fusion were knocked down to sixth overall, but that's still good for a playoff berth.

None of that dampened the ardor of  Ben Mascioli, 26, who took the concept of fusion literally and popped the question to his longtime girlfriend and fellow gamer, Caitlin Jaworski, 24.

"Will you be the Mercy to my Genji?" he asked, referring to two popular Overwatch​ characters.

She said yes.