Guido Vianello shook off some rust during his first fight in more than a year and recorded another knockout Saturday night.

The 2016 Olympian from Italy stopped Mexico’s Rafael Rios late in the fourth round of their heavyweight fight on the Isaac Dogboe-Joet Gonzalez undercard at Grand Casino Hinckley in Hinckley, Minnesota. The 6-foot-6, 244-pound Vianello dropped Rios late in the fourth round, which caused referee Tyrone Roberts to stop their scheduled eight-rounder with one second left in it.

The 28-year-old Vianello (9-0-1, 9 KOs) ended a layoff that lasted almost 13 months. His hiatus was mostly caused by surgery on his right hand.

Tijuana’s Rios (11-4, 8 KOs), who boxed for the first time in 20 months, lost a second straight bout by knockout or technical knockout. Puerto Rican veteran Carlos Negron knocked out Rios in the second of Rios’ previous fight, which took place in November 2020.

Vianello displayed his full arsenal while beating up Rios throughout the fourth round. A right to the side of Rios’ head, followed by a left to his body, made Rios take a knee with eight seconds remaining in the fourth round.

Rios, who was bleeding from his nose, beat the count, but Roberts waved an end to the action because Rios wasn’t fit to continue.

Vianello’s right uppercut made Rios step backward with 25 seconds to go in the fourth round.

Vianello blasted Rios with a right hand to the side of his head 50 seconds into the fourth round. Another right hand by Vianello caught Rios flush a few seconds later.

A clubbing right hand by Vianello got around Rios’ guard 45 seconds into the third round. Vianello’s short left uppercut connected with just over 50 seconds remaining in the third round.

A right-left combination by Vianello made Rios hold him as the bell sounded to end the third round.

A right by Vianello landed to the side of Rios’ head with just under a minute on the clock in the second round.

Vianello missed most of his power punches in the first round. He did back up Rios with a right hand, however, with just over 40 seconds to go in the opening round.

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