Atitlan continued his improvement by swooping from near the back of the pack with Hector Berrios to score a 9-1 upset in the $100,000, Grade III San Luis Stakes at Santa Anita on Saturday.
A 4-year-old who was the youngest horse in the 1 1/2-mile turf race for 4-year-olds and up, Atitlan ($20.20) won for the first time in four starts since the Grade II Twilight Derby last October.
John Shirreffs trains the son of The Factor.
Divin Propos finished second, Gold Phoenix third in his 7-year-old debut, favorite Easter fourth in the field of eight.
Sunday, Casalu (Flavien Prat riding) will try to become the first three-time stakes winner at the nearly three-month-old Santa Anita meet when she faces Will Then (Umberto Rispoli) and three others in the $100,000 China Doll Stakes for 3-year-old fillies at 1 mile on turf.