Logician maintained his unbeaten record with an emphatic victory in the William Hill St Leger at Doncaster.
Ridden by Frankie Dettori - who was winning the world's oldest Classic for the sixth time - the John Gosden-trained son of Frankel was sent off the red-hot 5-6 favourite, following his most recent victory in the Great Voltigeur at York.
That win on the Knavesmire last month had come on the back of success in a Newbury handicap, and the Khalid Abdullah-owned colt duly took this step up to the highest level with aplomb.
Nestled towards the rear through the early stages, Dettori took his time before moving sweetly down the Town Moor straight and sweeping to the front when he asked the grey to quicken a fair way out.
Sir Dragonet briefly threatened to make a race of it. But in the end there was only one horse in it, with Dettori able to ease up close home for a two-and-a-quarter length success from Sir Ron Priestley, who ran a big race for Mark Johnston in the hands of Franny Norton.
It was another head back in third to Nayef Road, also trained by Johnston.
Dettori was winning the oldest Classic for the sixth time in his brilliant career.
He told ITV Racing: "That was probably my easiest win (in the race), and he is a serious horse.
"The ground was a bit dry for him - they went fast and tried to test my stamina.
"For a split second I thought he might not pick up - but then he did. From two out, I knew I'd won. He's the favourite - there's 30,000 people, and he delivered.
"I wasn't sure (he'd stay), I'll be honest, but I think he is just a bit above these horses."
As for his own season to date, Dettori added: "It's unbelievable really."
