Michael Spinks vs. Steffen Tangstad was a professional boxing match contested on September 6, 1986, for the IBF, The Ring and lineal heavyweight titles.

[1] Michael Spinks, in his first fight in the Don King and Butch Lewis-promoted heavyweight unification series, made the first successful defense of his IBF heavyweight title on April 19, 1986, by scoring a split decision victory over Larry Holmes, whom he had previously defeated the previous September to capture the title, in an IBF-mandated rematch rematch.

Though Tangstad, now bleeding from the nose, was able to get back up, he informed referee Richard Steele that he did not continue and the fight was stopped, giving Spinks the victory by technical knockout at 58 seconds of the round.

[10] After his victory over Tangstad, Spinks controversially exited the heavyweight unification series and instead agreed to face Gerry Cooney.

[12] After a several month-long legal battle, a judge lifted the injunction in March 1987 and Spinks finally met Cooney in June of that year, knocking him out in the fifth round.