Blair Oster and Cory Chambers are both from North Battleford, Sask., and have known each other since elementary school. They met inside the ring at a local mixed martial arts event, Saturday Night Fights 13, this past weekend in Regina, the Canadian province’s capital city. Leading up to the bout, there was no animosity between the two lightweights, but all that changed after the night was over.

At the beginning of their co-main event bout, Chambers reached out to touch gloves, and Oster began to the the same, only to pull his arm back and instantly land a devastating overhand right on Chambers, wobbling his opponent. After Chambers fell to the canvas, Oster followed up with ground-and-pound and the referee was forced to call off the controversial contest. Check out video of the fight above, or by clicking this link.

Chambers told BloodyElbow.com that ahead of the bout, he agreed with Oster to touch gloves at the beginning of their fight. Oster did not immediately return a request for comment.

Per promoter AJ Scales, a rematch between Oster and Chambers will be scheduled for a to-be-determined event and date.

Saturday Night Fights 13 took place live from Turvey Centre in Regina, Sask., on May 13.