Mazilier came from the back of the pack and took the lead down the stretch Saturday to win the $82,500 San Simeon Handicap at Santa Anita before a crowd of 40,629.
Mazilier, ridden by Patrick Valenzuela, was timed in 1:15 4/5 for the 6 1/2-furlong race for 4-year-olds and up on the hillside turf course.
Owned by Juddmonte Farms and trained by Eddie Gregson, Mazilier beat Imperial Star by 1 1/4 lengths to earn $48,750 and pay $5.40, $3.80 and $3.00.
Imperial Star, ridden by Bill Shoemaker, paid $6.40 and $3.60.
Shoemaker was trying for his 1,000th stakes victory after scoring No. 999 Thursday in the Montclair Handicap at Golden Gate Fields. The veteran rider has said he will retire at the end of this year.
Caballo de Oro, ridden by Rafael Meza, was third by a head and paid $3.60.
Kentucky-bred Mazilier started slow in the field of eight and drew near the leaders at the halfway point before drifting wide in the turn to the stretch.
Five horses headed into the stretch side-by-side before Mazilier took control.