Trainer Pascal Bary worked the Dansili colt over nine furlongs at his Chantilly base on Saturday morning and expressed satisfaction at the outcome.
Bary has never won the much-coveted Longchamp showpiece but is adamant Zambezi Sun has made immeasurable progress since third to Soldier Of Fortune in the Prix Niel.
“He went well on Saturday morning, very good indeed, and I think he has improved greatly since the Prix Niel,” said Bary.
“Between now and the Arc we are going to rest him and he will do nothing much before the race.
“He’s in good form and things should be in his favour in Paris.”
Zambezi Sun, a classy scorer in the Grand Prix de Paris on his penultimate start, is a 9-2 shot with totesport as owner Khalid Abdullah targets a second consecutive victory in the Arc.
Youmzain is considered one of the outsiders of the field but boasts some solid, if unpredictable, form at the highest level.
A Group One winner in Germany last year, Mick Channon’s four-year-old finished an honourable second in the King George VI And Queen Elizabeth Stakes – only to disappoint at Baden-Baden last month.
“It’s all systems go for the Arc and Hughesy (Richard Hughes) rides,” declared Channon.
“I don’t think he’s had much racing. It was on fast ground last time and things didn’t go right.
“That’s racing for you and if the others don’t perform, he can pick up the pieces.
“He’ll turn up and he’ll run his race,” the West Ilsley handler told At The Races.
Smart German colt Saddex will complete his preparations with a spin on this morning.
Peter Rau’s four year old catapulted into the Arc equation at Cologne, where he made short work of the likes of Laverock in the Group One Rheinland-Pokal.
Coral bet: 5-4 Authorized, 3-1 Soldier Of Fortune, 9-2 Zambezi Sun, 7-1 Dylan Thomas, 11-1 Mandesha, 14-1 Saddex, 20-1 Bar