Showtime had been in business for a decade when it started with boxing as a live programming event in March 1986.

Showtime Championship Boxing made a long climb from startup, to worthy challenger to HBO as TV's main source for top-flight boxing, to driving HBO from the boxing business in 2019.

The reopened and much-refurbished Minneapolis Armory hosted its first boxing card in April 2018. Since then, there have been a dozen Premier Boxing Champions cards at the Armory, all through PBC's tie-in with Fox and FSI.

The next two PBC cards are set for the Armory — this Saturday night and June 4 — and they will be Showtime events, which is fully the big leagues for boxing.

On Saturday, the two headline events feature super welterweight Tim Tszyu, 20-0 with all previous bouts in his homeland of Australia, and lightweight Michel Rivera, 22-0.

Tszyu, 27, will be facing Terrell Gausha, 22-2-1, a 2012 U.S. Olympian. Tszyu is a minus-$700 (to win $100) in Las Vegas sportsbooks, even though Gausha, 34, revitalized his career with a second-round TKO of Jamontay Clark last March.

Tszyu is the son of former champion Kostya Tszyu. Was it his father's influence that got Tim to the point a potential world title bout?

"He tried to keep me out of boxing,'' Tszyu said. "I was in gymnastics as a young kid and then played [Australian rules] football. My father didn't like the brutality of boxing, not for his son.''

Igor Goloubev is Tszyu's uncle and has been his trainer since Tim started boxing as a teenager. Tszyu spent two weeks working in gyms in Las Vegas to prepare for his first U.S. fight.

"Some work in Floyd Mayweather's gym, some in another gym … it has been very good,'' Tszyu said. "I'm ready to put on a show for a U.S. crowd.''

Rivera's opponent in the 10-round bout will be Joseph Adorno, also unbeaten in 16 fights but with draws in his previous two fights.

Rivera is a minus-$370 favorite and expects a WBA title fight with a win.

Showtime's June 4 card at the Armory has a title fight that's much anticipated with the hard-core boxing crowd:

Stephen Fulton Jr. will be putting his unified super bantamweight title on the line against former champion Danny Roman.

David Morrell Jr., the Cuban middleweight, will also be defending his title that night against Kalvin Henderson (15-1-1). Morrell, 6-0 with five knockouts, was living and training in Minneapolis until last November. He's now training with Ronnie Shields in Houston.