They won the Transvaal Knock-out Trophy, his first trophy in a successful union career. By 1949, when international rugby returned to South Africa, he represented the senior Diggers side that claimed the Pirates Grand Challenge Trophy. In 1949, Rens made his debut in a series of inter-province friendlies. This launched his 81 game career for his province.
He also won a place in the Transvaal Urban XV against the touring All Blacks. In 1952, when Transvaal played Boland in the Currie Cup Final at Wellington in October, Rens scored the critical drop-goal to seal the game and an 11–9 win. He also kicked a penalty and conversion for a total of eight points. With the 1953 Australian tour, Rens won his Springbok colours (Springbok #310) and played against the tourists in two tests.
By the end of the 1960 season, after 12 provincial seasons, 291 points and 14 tries, his rugby union career was over. With the launch of the rugby league in South Africa in 1962, Rens became one of the pioneers of the 13-man code locally and he captained the Southern Suburbs side in the competition of Rugby League South Africa. He played in the first match against the British Lions in August 1962 at stand-off and toured Australia and New Zealand with the Rugby League Springboks in 1963.
By Hendrik Snyders