On the eve of the biggest fight in 2015 (or years for that matter), a world title fight will be on the line, along with a bout between unbeaten fighters.

Ray Beltran and Takahiro Ao wil square off for the vacant WBO lightweight title on May 1 inside the Chelsea Ballroom at The Cosmopolitan in Las Vegas, Nev., Top Rank matchmaker Brad Goodman told RingTV.com.

In his last fight on Nov. 29, Beltran (29-7-1, 17 knockouts) lost a 12 round unanimous decision to Terence Crawford. After the fight, Crawford announced he was vacating the title and moving up in weight to 140 pounds.

Some in boxing thought Beltran should have won the WBO title in Sept. of 2013 when he fought Ricky Burns in Glasgow, Scotland. Instead, Beltran and Burns fought to a highly-disputed draw.

Burns lost the title to Crawford on Mar. 1 of last year.

Ao (27-3-1, 12 KOs), who is a former titleholder at featherweight a junior lightweight, has won his last four bouts in a row since his Oct. of 2012 upset loss to Gamaliel Diaz. In his last bout on Oct. 22, Ao won a 10 round unanimous decision over Juan Carlos Salgado.

Ao’s other losses have been to former world title-holders Oscar Larios and Elio Rojas.

In a 10-round bout featuring unbeaten welterweights, Mikael Zewski will fight Konstantin Ponomarev.

The French-Canadian Zewski (26-0, 20 KOs) will be defending his NABF welterweight title. In his last bout on Dec. 13, Zewski defeated Jeremy Bryan by majority decision over 10 rounds.

In his last bout on Jan. 24, the Russian-born Ponomarev (27-0, 13 KOs) won a hard-fought eight round unanimous decision over Steve Claggett.

Francisco A. Salazar has written for RingTV since October of 2013 and has covered boxing in Southern California and abroad since 2000. Salazar also covers boxing for the Ventura County (CA) Star newspaper, RingTV, and Knockout Nation. He can be reached by email at [email protected] or on Twitter at FSalazarBoxing