Featherweight Gary Russell Jr., Egis Klimas, manager of Ukrainian rival Vasyl Lomachenko, and Golden Boy Promotions Vice President/matchmaker Eric Gomez have all informed RingTV.com that the fighters have signed to fight on June 21 for the WBO's vacant featherweight belt at the StubHub Center in Carson, Calif.

On April 18, Golden Boy out-bid rival Top Rank by a mere $2,500 — $1,052,500 to 1,050,000 — for the right to stage Russell-Lomachenko.

"Both guys have signed. We won the purse bid and our attorney, Arnold Joseph prepared the agreements and sent them out," said Gomez. "It's going to be at the StubHub Center and it's going to be on Showtime. There are certain rules and regulations when you win a purse bid…We complied with the rules and the fight's on."

A 25-year-old from Capitol Heights, Md., Russell is 24-0 with 14 knockouts.

"I've signed my contract probably about a week-and-a-half ago," said Russell, "so I'm ready to fight. It's going down. I'm most definitely ready to rumble."

A 2008 U.S. Olympian, Russell (he qualified for the team but never competed due to missing the weigh-in) was declared by WBO President Francisco "Paco" Valcarcel in October to be the WBO’s mandatory challenger to face then-beltholder Orlando Salido.

The ruling did not preclude Salido from making a voluntary defense against Lomachenko, which he did on March 1. Lomachenko fell by split decision but Salido lost his belt at the scales after failing to make the 126-pound weight limit.

As a result, the title became vacant.

Lomachenko, 26, had said he had wanted to make history by becoming a titleholder in what was being billed as his second professional fight. According to Fight Fax Inc., Lomachenko is actually 7-1 because he was paid to take part in six World Series of Boxing contests.

"We can say a lot of things but the fight is the fight," said Klimas. "Usually, we don't like to talk too much before the fight. We don't want to say any predictions. We just want to go and do our job and see what's going to happen."