The British Olympic show jumper was found guilty in September of inadvertently doping his stallion Tackeray (news, 1 October).
His ban started in June, when the International Equestrian Federation (FEI) announced it had found traces of altrenogest, a substance banned for use in stallions, in a random sample taken in May.
Competing at the Sycracuse Invitational Sporthorse Tournament in New York last weekend, Michael made a winning return in the CN Gambler’s Choice — a fancy-dress, top-score competition — on Udokus.
He also finished fourth in the three-phase Sporthorse Cup on Insul Tech Wonami Van Den Aard.
• A full report from the competition will appear in H&H on 12 November