LAS VEGAS – Petros Ananyan pulled of a huge upset Saturday on the Deontay Wilder-Tyson Fury undercard.

The unknown Armenian veteran scored a knockdown against Puerto Rican knockout artist Subriel Matias late in the seventh round and beat him by unanimous decision in a 10-round welterweight fight at MGM Grand Garden Arena. Each judge – Lisa Giampa (95-94), Patricia Morse Jarman (96-93) and Don Trella (95-94) – scored their fight for Ananyan (15-2-2, 7 KOs), who won a unanimous decision.

Puerto Rico’s Matias had knocked out each of his first 15 professional opponents (15-1, 15 KOs). Had he not suffered that seventh-round knockdown, their bout would’ve been declared a majority draw.

Ananyan couldn’t capitalize in a nondescript eighth round on the knockdown he recorded late in the seventh. Ananyan pressured Matias throughout the ninth and 10th rounds as well, but he couldn’t connect with the type of thudding right hand that started the trouble for Matias in the seventh round.

Matias’ right-left combination rocked Ananyan late in the seventh round, but Ananyan nearly knocked him out toward the end of that round. Ananyan landed four hard, chopping rights to the side of Matias’ head and blasted Matias with a left hook that knocked him backward, into the ropes.

Because the ropes held up Matias, referee Robert Byrd counted it as a knockdown. The count took a little longer than usual because Byrd had to tell Ananyan more than once to go to a neutral corner.

The seventh round ended before Ananyan could follow up on hurting Matias.

A left hook by Matias wowed the crowd early in the sixth round and knocked Ananyan off balance. Byrd warned Matias for landing a left below Ananyan’s belt with about 45 seconds to go in the sixth.

Matias blocked a lot of the punches Ananyan threw when they fought inside during the fourth and fifth rounds. Matias connected with a hard right and hard left to the body late in the fifth, but Ananyan fired back with a right up top that landed.

Matias landed a hard left to the body late in the third round, but Ananyan took it well. Matias and Ananyan traded hard shots toward the end of the second round.

Ananyan wouldn’t give any ground during the opening round, which was a sign of the type of fight he would give the hard-hitting, heavily favored Matias.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.