Treve had five lengths in hand over favourite Orfevre, finishing second again after beaten a neck last year, as jockey Thierry Jarnet completed a hat-trick of Arc victories despite only taking the ride late last week after Frankie Dettori suffered a season-ending injury.
Head-Maarek, who first won Europe's richest race with Three Troikas in 1979, was full of praise for her unbeaten horse who has now won the French Oaks, Prix Vermeille and the Arc in one season.
"The way she won was incredible because she didn't have the best of races. She was never covered up. She had to come on the outside all the way," the 64-year-old told Channel 4 television.
"It leads you to think that when horses are good, numbers at the start make no difference and the ground, no difference."
She also had a mention for the stricken Dettori, thanking him for the way in which he rode Treve in the Prix Vermeille.
"I want to say thank you to Frankie Dettori because he rode an amazing race on her in the Vermeille - he saved her for today."
Japan is still seeking an elusive Arc victory after Orfevre, trained by Yasutoshi Ikee, could not match Treve's acceleration at the business end of the race.
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