Ja'Rico O’Quinn needed just one punch to erase a massive scorecard deficit.

A counter right hand after taking a straight left hand was enough for Detroit’s O’Quinn to ruin the U..S. debut of Liverpool’s Peter McGrail, who was knocked out in the fifth round. O’Quinn was down twice and lost every round before he sent McGrail down and through the ropes to produce the end of the fight at 2:19 of the fifth round.  

The junior featherweight bout opened a four-fight DAZN telecast Saturday evening from Desert Diamond Arena in Glendale, Arizona.

“I knew I wouldn’t get a decision. All I needed was one, and that’s all she wrote,” O’Quinn told DAZN’s Chris Mannix after the improbable victory.

McGrail arguably won every minute of the fight prior to that disastrous sequence. The 27-year-old southpaw—who represented Great Britain as a featherweight in the delayed 2020 Tokyo Olympics—consistently beat O’Quinn to the punch in an active opening round that showed off the Scouser’s terrific footwork.

O’Quinn was decked midway through the second round, though replays revealed that it was more of a trip. Nevertheless, he found himself in an early hole on the scorecards. Things grew worse in round three, as McGrail connected from all angles.

McGrail produced a clean knockdown early in round four. A straight left hand sent O’Quinn to the canvas for the second time on the night. He made it out of the round without any further damage but was instructed by his corner to let it rip and not hold back.

Those orders were followed to a tee.

McGrail was still in control and even landed a straight left hand as O’Quinn was cornered. The shot worsened a cut over the left eye of O’Quinn, who paused before he launched a right hand to end the fight.

"He cherry picked me and said 'I'm perfect for him." Look at what happened.,” noted O’Quinn, who advanced to 17-1-1 (9KOs) with his third straight win. “That's what happens when you pick the wrong cherry."

McGrail fell to 8-1 (5KOs) with the crushing defeat.

Headlining the show, IBF flyweight titlist Sunny Edwards (20-0, 4KOs) and WBO claimant Jesse ‘Bam’ Rodriguez (18-0, 11KOs) collide in a scheduled twelve-round unification bout between unbeaten title holders.

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox