ASCOT, England (AP) — Lethal Force sprinted to victory Saturday by two lengths in the Diamond Jubilee Stakes, the headline race on the fifth and final day of Royal Ascot.

Adam Kirby rode the Clive Cox-trained horse into a clear lead over favorite Society Rock with 50 meters to go. Despite his main rival making a late dash, Lethal Force cruised home.

"He's special, we always hoped he was, and Adam is such a brilliant rider," Cox said

Society Rock held on for second, with Krypton Factor finishing third.

The winner of the Hardwicke Stakes, Thomas Chippendale, died of a suspected heart attack shortly after the end of the 1 ½ mile Group Two race on Saturday.

Thomas Chippendale, in his 10th career race, won the King Edward VII Stakes at Ascot last year.

Ridden by Johnny Murtagh, the four-year-old colt was trained by Lady Cecil, wife of the leading British trainer Henry Cecil who died on June 11.

"He ran his heart out and was pulled up at the line," Murtagh said. "He lost his balance and I don't know what happened to him."