LAS VEGAS -- Raymundo Beltran plowed through Takahiro Ao, delivering a bruising second-round knockout Friday night at the Cosmopolitan of Las Vegas, but he did not win the vacant lightweight world title at stake because he failed to make weight Thursday.
The belt will remain vacant because Beltran weighed in at 135.4 pounds, .4 over the 135-pound lightweight limit.
From the outset, he looked much stronger and thicker than Ao, a southpaw and former featherweight and junior lightweight world titleholder from Japan.
Beltran (30-7-1, 18 KOs), 33, of Mexico and living in Phoenix, pushed Ao around in the first round as they engaged in some fierce exchanges. Beltran kept getting though with left hooks and rocked the 31-year-old Ao (27-4-1, 12 KOs).
In the second round, Beltran hammered Ao with a flush overhand right hand on the chin, and Ao went down hard. He got to his knees and barely beat the count. When the fight resumed, he was in trouble immediately, as Beltran was all over him.
Beltran ripped him with a series of hard left hands on the ropes, finally forcing referee Tony Weeks to step in and stop the bout at 1 minute, 29 seconds.
"At the start of the fight I really didn't feel that well from my weight loss and my legs didn't feel right," Beltran said. "But then I caught him solid with an overhand right [in the second round] and I finished him off with combinations. This is a super big win for my career.
"I can't remember the last time I had a knockout like this. He was a two-time world champion and I knew what I was up against but I caught him just right."
The fight served as the main event of the debut card of Top Rank's new "Metro PCS Friday Night Knockout" series on truTV.
The belt was vacant because 2014 ESPN.com and Boxing Writers Association of America fighter of the year Terence Crawford, who was ringside (and who had outpointed Beltran in a title defense last year), vacated the title to move up to junior welterweight, where he knocked out Thomas Dulorme on April 18 to win a vacant 140-pound world title.
Had Beltran made weight, he would have won a word title in his third shot at one. In September 2013, he traveled to Scotland to challenge then-titleholder Ricky Burns but was held to a draw in a fight that most thought Beltran had won handily. Two fights later, Beltran got a mandatory title shot against Crawford, who had dethroned Burns. Beltran traveled to Crawford's hometown of Omaha, Nebraska, and lost a one-sided decision in November.
In the co-feature, welterweight Konstantin Ponomarev (28-0, 13 KOs), 22, of Russia, outfought Mikael Zewski (26-1, 20 KOs), 26, of Canada, to win a unanimous decision in an entertaining fight. Ponomarev consistently beat Zewski to the punch and swelled his left eye on the way to winning by scores of 99-91, 98-92 and 97-93.