The five-year-old was surprisingly running over the minimum distance for the first time in his career, and the pace was red hot in the early stages of the race.
Wesley Ward's Maven struggled to keep tabs on the flying females Que Amoro and Winter Power, but as Que Amoro began to weaken, Winter Power was left in front. Jim Crowley appeared to have her covered on Battaash with a furlong to run.
However, was making his seasonal debut, failing to pick up when Crowley asked for an effort and he was eventually swamped.
The 4/1 shot Oxted had been under pressure for a while but powered through close home to win going away by a length and three-quarters from Arecibo and American raider Extravagant Kid under Frankie Dettori.
It was a first Royal Ascot winner for both trainer and jockey, the son of six-times champion Kieren Fallon who himself enjoyed so many memorable days at the showpiece meeting.