By Jake Donovan

Petr Petrov managed to outlast Marvin Quintero long enough to force a stoppage win after the 6th round of a brutal slugfest Friday evening at Toshiba Plaza in Las Vegas, Nevada. 

There was a sense of urgency from both lightweights who were forced to fight through rapid eye swelling. That moment came much earlier in the night for Quintero, whose left eye was slammed shut in the opening round courtesy of a sweeping right hand from Petrov.

The early injury provided Quintero with an early sense of urgency. The veteran southpaw boxer from Mexico came out firing in round two, landing the more telling blows and forcing Petrov into reactionary mode rather than taking the lead. By round three, the Russian-bred lightweight who now lives in Spain had to contend with Quintero's aggression and swelling around his right eye. 

It made for fun two-way action to that point and through the rest of the fight. Both had their say in a terrific round five in which neither fighter would back down no matter how painful was the incoming. Quintero unloaded in round six, but emptied his clip a bit too early as he was running on fumes while Petrov turned the tide in the final 30 or so seconds. 

Given that, it was the right call to stop the fight prior to the start of round seven. Quintero's eye was sufficiently monitored throughout the fight, with the ringside physician deciding he had taken enough after six bruising rounds. 

Because a clear cut ruling had never been made by referee Jay Nady, confusion ensued as to what exactly was the final outcome. Petrov climbed the turnbuckle as if to celebrate a knockout win, while Quintero insisted to anyone who would listen that the wound was caused by a headbutt. 

The officials agreed with Petrov's view in the end, with the official time coming at 3:00 of round six.

Petrov improves to 37-4-2 (18KOs). The win is his fifth straight, but just his second fight since taking top honors in the 2014 ESPN2 Boxcino Liightweight tournament. His last loss came in April '13, dropping a 12-round decision to unbeaten Dejan Zlaticanin, who fights for a vacant lightweight title in June. 

Quintero continues to run into bad luck. A little more than a year after having to quit after five rounds due to rolling his ankle in a stoppage loss to Jose "Chelo" Gonzalez, the 29-year old from Tijuana snaps a two-fight win streak as he falls to 28-7 (24KOs). 

The bout headlined a full night of boxing which streamed live on RingTVLive.com, with the main event and select bouts airing live on Estrella TV. 

UNDERCARD

Alan Sanchez had his way with Pablo Cesar Cano, but was forced to settle for a split decision win in their 10-round welterweight bout. 

Judge Dave Moretti somehow had Cano winning 96-94, further proving he's best served for the minor leagues in the twilight of his officiating career. Tim Cheatham and Kermit Bayless paid proper attention to the bout, scoring 97-93 in favor of Sanchez (18-3-1, 9KOs), who has now scored six straight victories.

Erik Ruiz and Horacio Garcia battled to a 10-round split decision draw in a spirited super bantamweight affair.

Scores were 98-92 Ruiz, 97-93 Garcia and 95-95 even. The fight was back and forth throughout the evening. Ruiz (15-5-1, 6KOs) turned the tide big time in the later rounds, rocking Garcia (30-1-1, 22KOs) on a number of occasions and responding well to trainer Robert Garcia (no relation to Horacio) urging him during and between rounds to not leave anything to chance. 

Most observers were okay with the draw verdict, not so much with the wide score cards in opposite directions. 

Jake Donovan is the managing editor of BoxingScene.com. Follow his shiny new Twitter account: @JakeNDaBox_v2