Michael Spinks vs Oscar Rivadeneyra

On November 25, 1983, Michael Spinks defended his unified WBC and WBA light heavyweight titles against Oscar Rivadeneyra at the Pacific Coliseum in Vancouver, British Columbia. This bout, promoted by Butch Lewis Productions, marked Spinks' first defence since he unified the light heavyweight titles with a victory over Dwight Muhammad Qawi nine months earlier.

Spinks, a 27-year-old native of St. Louis and the 1976 Olympic Gold medalist entered the fight with an undefeated record of 23-0-0 and weighed in at 173¾ lbs. His opponent, Oscar Rivadeneyra from Lima, Peru, was also undefeated at 19-0-0, with 15 of those wins coming by knockout, although his opponents were not as formidable as Spinks. Rivadeneyra weighed in at 173¼ lbs.

The fight was refereed by Joe Cortez, with judges Nicasio Lorenzo Drake and Isidro Rodriguez scoring it. Despite Rivadeneyra's aggressive start and some notable rounds, Spinks' experience and conditioning eventually took their toll. Rivadeneyra, who had never been knocked down in a professional fight before this bout, began to suffer from significant blood loss, particularly around his left eye, which impaired his vision.

By the tenth round, the situation had become critical for Rivadeneyra. At 1:42 into the round, Joe Cortez stopped the fight due to Rivadeneyra's inability to continue, declaring Michael Spinks the winner by TKO. The scorecards at the time of the stoppage were 89-82 for Cortez, 88-85 for Drake, and 89-86 for Rodriguez, all in favor of Spinks.

This victory marked Spinks' seventh title defence in 27 months since claiming the WBA crown from Eddie Mustafa Muhammad in July 1981. Spinks earned a significant purse of about $500,000, while Rivadeneyra received around $100,000, his highest payout to date.