Ridden by Richard Hughes for trainer Richard Hannon, the Arakan colt capped his juvenile campaign and took his untarnished record to three wins as he sailed across the finish line 2 3/4 lengths clear of Keeneland Phoenix Stakes (Ire-I) victor Sudirman, the second favorite.
One-paced maiden winner Giovanni Boldini finished 1 1/4 lengths back in third in the five-horse field.
Toormore covered seven furlongs 1:22.67 on turf rated as good.
"He's a big shell of a horse and is not a precocious 2-year-old by any means," Hannon said of Toormore, who won his career bow May 28 at Leicester.
Owner Middleham Park Racing enjoyed its first win at the group I level with Toormore, who in his previous start rallied from midfield to win the seven-furlong Veuve Clicquot Vintage Stakes (Eng-II) by a neck July 31 at Goodwood.
"We weren't sure what pace there would be in the (National Stakes), but as it turned out he got a fairly uncontested lead," said Tim Palin, racing manager of Middleham Park Racing.
"He has a great attitude and the further he goes the better he is. He's in the Racing Post Trophy (Eng-I, Oct. 26 at Doncaster) but will not run again this season. He's a very clean-winded horse, and could go straight for the (Two Thousand) Guineas (Eng-I) next year."
Bred in Ireland by Bec Bloodstock, Toormore is out of the unraced Danetime mare Danetime Out. He was bought by bloodstock agents Peter and Ross Doyle for £36,000 ($56,952 in United States funds) out of the Redpender Stud consignment at the 2012 Doncaster premier yearling sale.
Sire Arakan, a 13-year-old son of Nureyev, stands in Ireland at Ballyhane Stud.