Brock Jarvis avoided a nearly disastrous U.S. debut.

The unbeaten lightweight prospect from Marrickville, Australia survived a hellacious second round to regain control en route to a fifth-round stoppage of Mexico’s Alejandro Frias. A flurry of unanswered punches left Frias trapped in a corner, prompting a stoppage at 2:04 of round five which was deemed premature by the passionate crowd on hand Saturday evening at Chukchansi Park in Fresno, California.

Jarvis made his way stateside in his first fight with Matchroom Boxing, jumping out to an explosive start. Frias spent much of the opening round pinned against the ropes as Jarvis unloaded with hooks to the body and right hands upstairs, throwing every punch with knockout intentions.

It almost proved to be his undoing.

Jarvis’ blatant disregard for defense provided a key moment for Frias who went on the attack in round two. A combination upstairs sent Jarvis reeling into the ropes in a sequence that should have been ruled a knockdown. Frias let his hands go, battering the unbeaten Aussie in search of what would have served as one of the year’s biggest upsets.

The round ended with Jarvis slow to make his way back to the corner but with the benefit of fielding advice from trainer and Hall of Fame former three-division champion Jeff Fenech. The 23-year-old power puncher was urged to slow down and be smart with his combinations.

It worked to a degree, though more so as Frias appeared to punch himself out. The veteran lightweight from Nayarit appeared to have missed his shot at an upset, spending the rest of the fight fending off a determined Jarvis who regained control and never looked back.

Referee Ed Collantes grew concerned with Frias’ body language, never more so than late in round five when he stopped responding to a Jarvis flurry. A stoppage was called with Frias still on his feet and the crowd displeased, though allowing the Mexican lightweight to leave the ring with his health intact.

Jarvis advances to 20-0 (18KOs) with the win, his third straight inside the distance.

The bout served in supporting capacity to the return of former four-division titlist Mikey Garcia (40-1, 30KOs), who faces Spain’s Sandor Martin (38-2, 13KOs) in a scheduled 10-round welterweight contest.

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