Terence Crawford and Viktor Postol to clash on July 23

WBO champion Terence Crawford and WBC king Viktor Postol will contest the lineal super-lightweight title in Las Vegas on July 23.

Omaha's Crawford (28-0-KO20) will meet Postol (28-0-KO12) under the bright lights of the MGM Grand and the Ukrainian wasted no time in beginning the mind games when he presented Crawford with a commemorative postage stamp.

Postol's trainer, Freddie Roach said: "Neither snow nor rain nor heat nor gloom of night nor Terence Crawford stays this Postol courier from the swift completion of unifying the titles."

Crawford responded: "There's only one place for junk mail and that's the shredder. I'm going to cancel your stamp and your reign as WBC champion on July 23.

"The new face of boxing isn't on that stamp, it's in front of you."

Promoter Bob Arum said anticipation around the fight would be enormous, having finally matched the "best fighters in the division".

"Not only are they two champions, they're undefeated and, without question, the two best 140-pounders around," he said. "And when the best fight the best, the public will respond."

Postol won the title with a 10th-round stoppage of Lucas Matthysse in October 2015 while Crawford has made two defences since stopping Thomas Dulorme in the sixth almost exactly a year ago.