Zempilas has been involved with the Seven Network's coverage of the Olympic Games since the 2000 Sydney Olympics, where he co-hosted "Tonight at the Games" with Bruce Abernethy for the Western Australia and South Australia markets. At the 2002 Winter Olympics, Zempilas called Steven Bradbury's win in the 1000m speed skating; Australia's first Winter Olympic Gold medal. Zempilas provided rowing and basketball commentary at the 2004 Athens Olympic Games and represented "Seven News" at the 2005 World Aquatics Championships. In 2006 he began presenting the AFL segment on the Seven Network program "Sportsworld" with David Schwarz. He called the speed skating event at the 2006 Winter Olympics with Bradbury and also commentated on Rowing, Canoe/Kyak and Basketball at the 2008 Summer Olympics.