Diesis, an English champion and prominent Kentucky stallion, was euthanized Nov. 18 at Mill Ridge Farm, owned by Alice Chandler and her husband, Dr. John Chandler, near Lexington. The 26-year-old pensioned son of Sharpen Up had fractured a hip the previous day. His condition worsened to the extent that it was in his best interest to euthanize him.Although he stood in Kentucky, Diesis' best runners were in Europe. His European champions included Halling, Magistretti, Docksider, Ramruma, Diminuendo, Elmaamul, and Three Valleys. Magistretti also was a grade I winner in the U.S.Diesis, whose progeny has earned more than $47.4 million, is represented by other North American grade I winners Husband, Storm Trooper, Continuously, and Rootentootenwooten.Diesis won the 1982 William Hill Dewhurst (Eng-I) and William Hill Middle Park (Eng-I) Stakes as a 2-year-old his championship season for breeder/owner Lord Howard de Walden. Diesis, who was produced from the Reliance mare Doubly Sure, covered six mares this year, four of which are in foal.