Zenyatta rallied from last in the early going and fought off Gio Ponti in the stretch to win by a length Saturday at Santa Anita, beating a loaded field of 11 males.
Ridden by Hall of Fame jockey Mike Smith, the 5-year-old mare ran 1¼ miles in 2:00.62 and paid $7.60, $5.60 and $3.80 as the 5-2 wagering favorite of the 58,845 fans.
Gio Ponti returned $9.20 and $6.60, while Britain-bred Twice Over paid $7 to show.
Belmont Stakes winner Summer Bird was fourth and Kentucky Derby winner Mine That Bird was ninth, extending his losing streak to five straight since his 50-1 upset on the first Saturday in May. Irish import Rip Van Winkle was 10th.
Quality Road, who was broken in Aiken by Ron Stevens, was scratched from the race.