Rene Tellez Giron knocked off another taller, favored fighter Thursday night.

The Mexican veteran dropped George Acosta in the fifth round, landed the harder punches consistently and won their eight-round lightweight bout by unanimous decision on the Teofimo Lopez-Jamaine Ortiz undercard at Mandalay Bay Resort and Casino’s Michelob ULTRA Arena in Las Vegas. All three judges – Dave Moretti (79-72), Eric Cheek (78-73) and Steve Weisfeld (76-75) – scored Giron the winner.

Giron (19-3, 12 KOs), of Queretero, Mexico, was approximately a 2-1 underdog. That didn’t stop him from ending Acosta’s 19-fight winning streak.

Prior to Thursday night, Acosta hadn’t lost since he dropped a six-round unanimous decision to Ruben Torres (then 8-0) in May 2019 in Corona, California.

Giron and Acosta slugged it out during the eighth and final round. By then, it seemed clear that Giron had done enough to win.

Acosta connected with body shots during the seventh round, but Giron drilled him with a left hook toward the end of it. An aggressive Giron continued to control the action in the sixth round and continued to build on his lead.

Giron’s right hand sent Acosta to the canvas a couple seconds before the halfway point of the fifth round. Acosta answered referee Raul Caiz Jr.’s count quickly and didn’t seem all that hurt once the action resumed.

An accidental head-butt later in the fifth round cause a cut on the right side of Acosta’s head.

A right uppercut by Giron landed with just over 40 seconds to go in the fourth round. Giron later caught Acosta with a left hook just before the fourth round concluded.

Giron caught Acosta with a right uppercut and a left hook a few seconds before a competitive third round ended.

Giron landed to Acosta’s head and body during the second round, when he came forward and sometimes swung wildly at his upright opponent.

Acosta worked effectively off his jab throughout the first round, when he tried to keep Giron at a distance. He landed a right to the side of Giron’s head with just over 40 seconds on the clock in that opening round.

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