Vasyl Lomachenko agreed to weight check to secure fight with Guillermo Rigondeaux

Junior lightweight world titleholder Vasyl Lomachenko wanted to face a top opponent so badly that he acquiesced to the request from junior featherweight titleholder Guillermo Rigondeaux during negotiations that there be a weight check on the day of the fight.

Lomachenko will put his 130-pound world title on the line against 122-pound titleholder Rigondeaux, who is moving up two weight divisions for a historic meeting, in the main event of the Top Rank ESPN card on Dec. 9 (ESPN and ESPN Deportes, 9 p.m. ET) at the sold-out Theater at Madison Square Garden in New York. But neither fighter will be allowed to blow up to more than 138 pounds immediately after the weigh-in, because at 9 a.m. on the day of the fight there will be a weight check, Top Rank vice president Carl Moretti told ESPN on Friday.

The weight clause in the contract had not previously been revealed.

"Rigondeaux's team broached the subject when we were negotiating the fight, so we went to Lomachenko and [manager] Egis [Klimas] with it," Moretti said. "Lomachenko and Egis said they had no problem with it, so it's in the contract."

Moretti then added, joking about Rigondeaux's defensive boxing style that includes a lot of movement, "And then we in turn asked that Rigondeaux run no more than three miles inside the ring the night of [the] fight."

If either Lomachenko or Rigondeaux weighs more than 138 pounds at the weight check there is a financial penalty, Moretti said. He declined to say exactly how but said, "Let's say it's more than $10,000."

Since Lomachenko, who also won a world title at featherweight, is not that much bigger than Rigondeaux, Moretti said adding the clause to the agreement was not a sticking point.

"It was one of the original negotiating points, and we had no problem with it," Moretti said. "I don't think there will be that big of a difference when they stand next to each other in the ring. There isn't a big physical size difference between them, and Lomachenko doesn't put on a lot of weight after the weigh-in anyway. Size is not what will determine the outcome of this fight.

"If the weight check was something that helped make the fight, which it did, then why not when it wasn't a big problem? It showed just how much 'Loma' really wanted this fight."

Lomachenko (9-1, 7 KOs), 29, who will be making his fourth title defense, and Rigondeaux (17-0, 11 KOs), 37, are two of the greatest amateurs in boxing history. Lomachenko was 396-1 and won Olympic gold medals for Ukraine in 2008 and 2012. Rigondeaux was 463-12 in the unpaid ranks and won Olympic gold medals in 2000 and 2004 for Cuba before defecting and turning pro in 2009. In addition to their Olympic success, they also both won two world amateur championships apiece.

Their fight will mark the first time that fighters who have each won two Olympic gold medals will fight in the pro ranks, and the result will have major implications to boxing's pound-for-pound rankings.