Ingrid Hornig's German-bred son of leading sire Galileo covered 4,000 meters (about 2 1/2 miles) in 4:24.38 on turf rated as soft in the final Thoroughbred race on the Qatar Prix de l'Arc de Triomphe (Fr-I) card.
Recent Doncaster Cup (Eng-II) winner Times Up finished third, six lengths behind Tac de Boistron.
The marathon was wide open on the home turn when French group II winner Tac de Boistron asserted himself. He looked poised to win until Altano threw down a strong challenge midstrech under Eduardo Pedroza and delivered a consolation victory to Andreas Wohler. The German trainer scratched stablemate Novellist from the Arc when he developed a fever the day before the race.
Wohler also sent out Grosser Preis von Bayern (Ger-I) winner Seismos, who checked in sixth in the 10-horse field. Last year's Prix du Royal-Oak (Fr-I, French St. Leger) winner Les Beaufs, the 3-1 favorite with Racing Post, faded to seventh at the front early.
Snapping a three-race winless stretch that included a runner-up finish in the Goodwood Cup (Eng-II) in August, Altano won the first group I race of his career in the Cadran after beginning the season triumphant in the Oleander-Rennen (Ger-III) May 19 at Hoppegarten. The 7-year-old gelding has a record of 12 wins, six seconds, and two thirds from 28 career starts.
Bred by Gestut Ittlingen, Altano is out of the Lando mare Alanda. He is a three-quarter brother to German stakes winner Araldo, who is group I-placed. Altano was a gift from Gestut Ittlingen to Hornig, who is their veterinarian.