Postponed has bounced back to his best to defeat Cox Plate placegetter Highland Reel in the Group One Juddmonte International at York.
Highland Reel had no response to Postponed's finishing kick and was beaten 1-1/4 lengths with Mutakayyef third.
"He's an incredible horse," winning trainer Roger Varian said.
"The team at home have done a fantastic job. In the last seven days he looks to have blossomed.
"I would think it unlikely he'll run again before the Arc. It will give us plenty of time to tune him up for that race."
Trainer Aidan O'Brien was pleased with the run of Highland Reel who looks set to resume his international career with a return to Australia for the Cox Plate.
"That was a very good run; we're delighted," he said.
"He is still progressing and physically he's getting stronger all the time.
"I'd say he'll do plenty of travelling. He is in the big Australian races and he could go somewhere before that. He's very versatile."
Highland Reel finished third behind Winx and Criterion in last year's Cox Plate before going to Hong Kong in December to win the International Vase.
G3 - Lowland S
Listed - Ibhayi Stakes
G3 - Northern Trotting Breeders Stakes
G1 - Pascoes The Jewellers Northern Oaks
G3 - The Founders Cup (1700)