As a junior, Hillebrand won the Victorian Under 19 Clay Court Singles Championships three years in a row. Up until that time, it had only been done once, by Neale Fraser. Hillebrand also won the Tasmanian State Under 19 Singles Championships in 1957. In the first round at
Wimbledon in 1963, he defeated
John Newcombe in five sets with the score 14–12, 9–7, 4–6, 4–6, 6–3.
Arthur Ashe then defeated him 5–7, 7–5, 11–9, 3–6, 6–3 in the second round. In 1964, Hillebrand and partner Clive Brebnor reached the men's doubles final of the
British Hard Court Championships, where they lost to
Cliff Drysdale and
Keith Diepraam in straight sets. Hillebrand had wins either in singles or doubles against
Frank Sedgman,
Neale Fraser,
Rex Hartwig,
John Newcombe,
Tony Roche,
Paul McNamee,
Peter McNamara,
Bob Hewitt,
Frew McMillan, and
Jaroslav Drobny. He also has wins over Davis Cup players Mark Cox (GB), Roger Taylor (GB), Keith Diepraam (South Africa), Beppi Merlo (Italy), Pierre Barthes (Fr), Daniel Contet (Fr), Micah Dubitsky (Israel), Andres Licis (Poland),
Christian Kuhnke (Germany), Juan Gisbert (Spain), and
Nikki Pilic (Yugoslavia). Singles tournaments he won include Monte Carlo, Chapel Allerton, Sutton Coalfield, Eastbourne, Hoylake, St. Annes-On-Sea, and Israel. He won the Irish International Doubles Championship with
Warren Jacques in 1961. After retirement as a player, Hillebrand captained the winning "A" pennant team of Liston/Esplanade to the Premiership of Melbourne, Victoria in 1966. ==Retirement==