If there is a better horse in the world than Zarkava this year, it is hiding some place where human beings do not have access. The Aga Khan's brilliant 3-year-old filly extend her perfect record to seven victories without a loss at Longchamp on Sunday, winning the world's richest turf race, the $5.5 million Prix de l'Arc de Triomphe with her usual exhilarating turn of foot, overcoming a slow start and weaving through traffic in the stretch to defeat last year's runnerup, Youmzain, by 2 solid lengths.