South African Marius Jonker's rise to the top of the refereeing tree has been a rapid one.

Born in Kimberley, Jonker grew up in Pietermaritzburg playing fly-half for Natal Country Districts and Pietermaritzburg Police before moving to Richards Bay on the Kwa-Zulu Natal north coast. He later played for the North Coast Rhinos from Empangeni and for Richards Bay before starting to officiate in 2000.

In 2004, he refereed at the Under-19 World Championship going on to take charge of the final, between France and New Zealand. The following year he made his debut in the Super 12 and Currie Cup and also officiated at the Under-21 World Championship in Argentina, where he refereed a semi-final.

In August 2005, Jonker made his international debut as he oversaw a Rugby World Cup qualifying match between Uganda and Zimbabwe in Kampala. The following year saw him referee in the Pacific Cup, mid-year as Fiji travelled to Italy and then he took charge of the final game played at the old Lansdowne Road as Australia played Ireland. He then went on to referee the Calcutta Cup match between England and Scotland at Twickenham in the Six Nations in March 2007.

His success saw him fast-tracked alongside fellow referees Wayne Barnes and Nigel Owens as they made their Rugby World Cup bow in 2007 in France. Jonker took charge of three pool matches including New Zealnd's drubbing of Scotland and was one of Jonathan Kaplan's assistants in the semi-final between France and England.

He is a fixture in the Super 14 competition and made history when he became the first referee to take charge of a match as a 'non-neutral' under SANZAR's policy of selecting officials on a merit-based system. That match saw the Bulls take on the Queensland Reds in February 2009.