Adelaide will continue to host V8 Supercars through 2021, the Australian series has announced.
The city was the venue for Formula 1's Australian Grand Prix from 1985 to 1995.
The street track was then revived in truncated form in 1999 for a V8 event, which has since become a series highlight and often formed the season opener.
Adelaide's new deal was announced at a launch event on Friday by South Australian Premier Jay Weatherill.
"I am pleased to announce that those negotiations have been successful," he said.
"The result is that the event is now secure in South Australia for an additional six years, taking its future up to and including a race in 2021.
"We are making a long-term commitment to Australia's greatest motorsport event."
The 2013 Adelaide V8 Supercars event takes place on 1-3 March.