The top two boxers in the world pound-for-pound — Roman “Chocolatito” Gonzalez and Gennady Golovkin — will once again fight on the same card.

Gonzalez, the pound-for-pound king, will defend his junior bantamweight world title for the first time when he takes on former titleholder and mandatory challenger Srisaket Sor Rungvisai on March 18 (HBO PPV, 9 p.m. ET) at Madison Square Garden in New York.

K2 Promotions managing director Tom Loeffler made the announcement Tuesday afternoon at the kickoff news conference at MSG to promote the card headlined by the much-anticipated bout between unified middleweight titleholder Golovkin (36-0, 33 KOs) and secondary titlist Daniel Jacobs (32-1, 29 KOs). The Golovkin-Jacobs fight was finalized last month, but the deal for Gonzalez-Sor Rungvisai was finalized during the weekend, Loeffler said.

There had been discussion that Gonzalez might meet Carlos Cuadras in a rematch of their exciting fight on Sept. 10, which Gonzalez won by unanimous decision to claim a 115-pound belt and a title in his fourth weight division. However, Gonzalez and his team elected to go with Sor Rungvisai with the winner obligated to face Cuadras.

“Many people consider Sor Rungvisai more dangerous or just as dangerous as Cuadras. This is not an easier fight than a rematch with Cuadras,” Loeffler told ESPN. “Roman and his team decided to fight Srisaket with the winner having to fight Cuadras.”

The 30-year-old Sor Rungvisai (41-4-1, 38 KOs), a southpaw from Thailand, will try to regain the 115-pound world title he once held. Sor Rungvisai knocked out Yota Sato in the eighth round in May 2013 to win the title, made one successful defense later that year and then lost the belt to Cuadras by eighth-round technical decision in May 2014. The fight was stopped because Cuadras was cut over his eye from an accidental head butt and unable to continue, but he was ahead on all three scorecards.

Sor Rungvisai went 1-3-1 in his first five professional fights, but has not lost since other than to Cuadras in a competitive fight with a fluky ending. Sor Rungvisai has won 14 fights in a row since, although he faced mainly low-level opposition during that streak.

“He is a very dangerous opponent for Roman and even though many of the U.S. fans might not know him, the boxing people know him,” Loeffler said. “When we have the combination of GGG and Chocolatito in arguably the toughest fights of their career on the same card, that’s the type of value we want to provide for the fans that come to Madison Square Garden or the fans who buy the card on HBO PPV.”

Golovkin and Gonzalez will be appearing on the same card for the fourth time in their past five bouts. And even though they were not on the same card on Sept. 10, they were on the same HBO split-site telecast, with Golovkin knocking out Kell Brook in the fifth round at the O2 Arena in London and Gonzalez winning the junior bantamweight belt from Cuadras at The Forum in Inglewood, California.

“This will be their fifth appearance on the same broadcast together. It’s a great combination when you have the two best pound-for-pound fighters in the world on the same show,” Loeffler said. “The fans can see the talent level these guys have. All four of these fighters are extremely talented. That’s a winning combination for the fans.”

In voting by ESPN.com’s a panel of boxing experts, Gonzalez ranks No. 1 pound-for-pound and Golovkin is No. 2.

Gonzalez (46-0, 38 KOs), 29, of Nicaragua, has earned his position, steadily moving up the scale by beating top opponents and winning world titles at strawweight, junior flyweight, flyweight and junior bantamweight.

He made four flyweight title defenses before moving up in weight and defeating Cuadras to claim a belt in his fourth weight division to become the first boxer from Nicaragua to accomplish that feat. He surpassed the three titles won by the late International Boxing Hall of Famer Alexis Arguello, a Nicaraguan national hero and Gonzalez’s idol, mentor and former trainer.