Les played rugby from the age of 10 to 30. He is described in Jack Pollard's book Australian Rugby Union: The Game and the Players as 'a tough, broad-shouldered prop-forward' with fine scrummaging and ball running skills.

He was in the Australian front row in 1963 for the first Test against England in Australia, played at the Sydney Sports Ground (now Aussie Stadium). Australia played sparkling rugby on a waterlogged field to win 18-9, Jack Pollard crediting Austin with a stirring contribution to the victory.

That year Les toured South Africa with John Thornett's Wallabies, but could not break into the Test team which boasted Australia's fine front-row combination of Jon White, Peter Johnson and Thornett himself who had moved from the second-row position. Les also toured New Zealand with John Thornett's 1964 Wallabies.

A product of St Aloysius College, Milson's Point, Les played all his club rugby with teams in the Mosman area - sub district with Mosman RUSC (1954-55) and district rugby with Northern Suburbs RUSC (1956-66) where he played 180 first grade games, winning 3 first grade premierships in 1960, 1963 and 1964.

Les represented the New South Wales Waratahs in 1961, 1963 and 1964. He played against Fiji in 1961 and played with the Australian Barbarian Club on several occasions. While living in North America, Les also played for Canada against Japan.