[5] Felix made his debut on 16 July 1949 for South Africa as a lock in the first test match at Newlands Stadium, Cape Town against the touring All Blacks, led by Fred Allen.
[3][6] Supported by vice-captain Cecil Moss, Du Plessis' team – which included Springbok greats Tjol Lategan, Hannes Brewis, Okey Geffin, and Hennie Muller – swept the series 3 – 0.
He was replaced by Basil Kenyon, possibly because the player-coach's Border team had emerged unbeaten from two encounters with the New Zealanders, with a 9–0 win and a 6–6 draw.
[5] Felix worked as a representative for South African Breweries, then relocated to Vereeniging to manage Mittal Steel Company's sport and recreation department.
Morné recalls his father as a gentle and retiring person, who only started watching his son play rugby once he was at Stellenbosch.