Dubai World Cup (UAE-I) winner Electrocutionist died of an apparent heart attack Saturday, several days after an abnormality was detected in the 5-year-old horse's heart. Dubai-based Godolphin Racing Inc. owned Electrocutionist, considered a top contender for the upcoming Breeders' Cup Classic Powered by Dodge (gr. I). "He appeared to be responding well to treatment, but during the night he suffered what seems to have been a fatal heart attack," Godolphin racing manager Simon Crisford said. "It is terribly sad. He was a great horse for Godolphin and a real stable favorite. He will be sorely missed by all of us." The Kentucky-bred son on Red Ransom won the $6 million Dubai World Cup (UAE-) -- the world's richest horse race -- March 25, and finished second in his last start, the King George VI And Queen Elizabeth Diamond Stakes (Eng-I) at Ascot July 29. Electrocutionist also finished second behind Ouija Board in the Prince of Wales' Stakes (Eng-I) at Ascot eight days earlier. "He was a wonderful, brave horse, a real pleasure to train," Godolphin trainer Saeed bin Suroor said. "He gave his best every time he ran and I will always remember the courage and class he showed in winning the Dubai World Cup. He was a champion." Electrocutionist won eight of his 12 career starts, including three Group Ones, and won more than $5.6 million. He was owned by Earle Mack and trained in Italy by Valfredo Valiani before being bought by Godolphin in November. He raced four times for the Dubai-based stable. His next start was to be the Emirates Airline Champion Stakes (Eng-I) at Newmarket Oct. 14.