Alberto ‘El Alacran’ Ruiz picked up a much-needed win in style.

The previously struggling lightweight scored a shocking fifth-round knockout of previously unbeaten 19-year-old lightweight prospect Jair ‘Kaiser’ Valtierra to breathe new life into his career. A check left hook put Valtierra down and out for the night at 0:39 of round five in their Telemundo-televised main event Friday evening at Auditorio Blackberry In Mexico City.

The locally based Ruiz—a proud member of Chiquita Gonzalez Boxing, named after and headed by the Hall of Fame former junior flyweight king—had lost three of his last five starts but entered as the clear crowd favorite. A section full of ‘Alacran’ supporters led the cheers, with Ruiz coming straight forward and repeatedly connecting with left hooks and right hands. Valtierra struggled to keep pace, attempting to fight at a distance but failing to land anything to keep Ruiz at bay.

The aggressive approach carried over in round two. Valtierra was able to offer more lateral movement in the round, though often found himself at center ring forced to trade with Ruiz. The story of the fight continued to be the left hook of Ruiz, which consistently landed over Vatierra’s guard.

Valtierra was able to slow down the action in round three, landing with a left hook of his own though with minimal impact. Ruiz took the shots well and continued to come forward without fear of the incoming, as was the case throughout a relatively tame round four.

The fight ended in an instant in round five. Valtierra walked into a trap, following Ruiz to the ropes and letting go with a right hand. A follow up attempt never found its mark, with Ruiz crashing home a compact check left hook on the inside to put Valtierra flat on his back. The fight was immediately halted without a count issued, as ringside medical staff rushed into the ring to tend to the fallen Valtierra.

Ruiz picks up by far the best win of his career, advancing to 11-3 (8KOs). Valtierra suffers his first career defeat, falling to 15-1 (8KOs).

Abraham Arreola (2-0, 2KOs) picked up his second early win in as many pro fights, stopping David Escudero in the 4th round of their bantamweight contest. A spirited affair came to a sudden halt, when Escudero was no longer able to continue due to cuts and accumulated punishment. 

Jake Donovan is a senior writer for Twitter: @JakeNDaBox