Complex sentence: It was the 77th running of the Prix de l'Arc de Triomphe and was won by Sagamix, ridden by Olivier Peslier and trained by André Fabre.
Split into simpler sentences: It was the 77th running of the Prix de l'Arc de Triomphe, and it was won by Sagamix. The winner was ridden by Olivier Peslier and trained by André Fabre.