Inspired by performances of Russian ballet troupes that he saw in Australia, he had already begun to develop the exuberant, energetic, and highly theatrical style that would become his trademark in later life.
Frederick Ashton, chief choreographer of the company, noticed him right away and cast him as a music hall hoofer in the Popular Song duet in Façade.
Then, in 1947, guest choreographer Léonide Massine chose him for the leading role of the Barber in a revival of his comic ballet Mam'zelle Angot, a lighthearted romp of amorous pursuits.
As a "whimsical, endearing little person in a tow-colored wig," Grant happily "bounced about the stage like a rubber ball," then collapsed in abject despair before winning the heart of the ballerina in the title role, danced by Margot Fonteyn.
[8] It was "Grant's distinction as a classical dancer, combined with his mastery of character, that enabled Ashton to develop what were usually subsidiary supporting roles—the bravura trick soloists—into key players in the main drama, often introducing a provocative sexual charge.
"[9] Notable roles with an erotic element were Bryaxis the pirate chief in Daphnis and Chloe (1951), Eros in Sylvia (1952), and Tirrenio the sea god in Ondine (1958).
[10] In the former, he leapt and twirled in a delirium of joy with his red umbrella; in the latter, transformed into an ass, he capered about in pointe shoes, simulating hooves, in an interlude with the lovestruck Titania, played by Antoinette Sibley.
He gave more than fifty performances in the title role of Michel Fokine's Petrushka, and he was acclaimed as the eccentric Doctor Coppélius and the mysterious Herr Drosselmeyer in Coppėlia and Casse Noisette, respectively.
In A Month in the Country (1976), based on Ivan Turgenev's comedy of manners, he offered a moving image of a lovelorn Russian husband, opposite Lynn Seymour as the heroine.
During his seven years there, he significantly enlarged the company repertory by acquiring works by Ashton, Cranko, MacMillan, Béjart, and other internationally known artists as well as by encouraging such young Canadian choreographers as James Kudelka, He also occasionally appeared on stage as Alain, Carabosse, and various characters in mime roles.
When Ashton died in 1988, he left the rights to Façade and La Fille Mal Gardée to Grant, who subsequently traveled widely, staging and coaching these ballets for various companies.
He was romantically attached to ballerina Nadia Nerina in his early years in London but abandoned her in 1953 in favor of an intense affair with Ashton, who had fallen deeply in love with him.