The Prix Foy is the Arc trial for older horses, and Orfevre won comfortably from 15-1 outsider Very Nice Name, coasting across the finish line by three lengths while covering 2,400 meters (about 1 1/2 miles) in 2:41.47 on soft turf.
Japan's 2011 Horse of the Year won last year's Prix Foy by a length from Meandre in his tuneup for the Arc, but in the main event, filly Solemia swept past him in the final strides in a heartbreaking upset.
Following a win by Kizuna in the Prix Niel (Fr-II) earlier on the card, Japan will be represented by two top contenders in this year's Arc. Japan-based runners have failed to deliver a victory in Europe's top middle-distance race on 11 previous attempts.
Making his first start in 5 1/2 months since winning a group II race in March at Hanshin, Orfevre was eager to race early under Christophe Soumillon, who settled in third to stalk fellow Japan runner Stellar Wind. The 5-year-old Stay Gold horse was ready to rally when asked and secured the easy win in the final furlong.
The Prix Foy/Arc double has been achieved in the same year by only two horses: Allez France in 1974 and Sagace in 1984. Exbury won the 1962 Prix Foy and took the Arc the following year.
The Arc is set for Oct. 6 at Longchamp, and Orfevre shares earlier favoritism with Treve, who won the Prix Vermeille (Fr-I) earlier on the card. Both are pegged at 4-1 with bookmaker Paddy Power. Bookmaker William Hill cut Orfevre's previous 5-1 odds to 11-4.
Trained by Yasutoshi Ikee for owner Sunday Racing Co., Orfevre, who is out of the Mejiro Queen mare Oriental Art, improved to 10 wins, four seconds, and a third from 17 career starts.
Three-time European classic winner Camelot was withdrawn from the Prix Foy due to the rain-softened ground conditions. Trainer Aidan O'Brien said he could be an Arc starter if the ground conditions are satisfactory on raceday at Longchamp.