France's Sebastien Bourdais clinched the 2005 Champ Car world title after winning the Gold Coast race.
Bourdais won five of the last six Champ Car races
Bourdais claimed back-to-back world titles after beating American AJ Allmendinger by 9.129 seconds over the Surfers Paradise street circuit.
American Jimmy Vasser was third, 31.851 secs behind Bourdais.
It was the Bourdais' sixth win of the season and he finished with 344 points in the championship standings, 78 ahead of Spanish team-mate Oriol Servia.
England's Justin Wilson was third with 231.
Bourdais could have won the title on Saturday, but he failed to qualify in pole position in Brisbane.
The final race of the series takes place in Mexico City on 6 November.
Gold Coast standings:
1. Sebastien Bourdais (Fra) in 1hr 39min 26secs
2. A.J. Allmendinger (USA) 9.129 of a second behind
3. Jimmy Vasser (USA) 31.851sec behind
4. Alex Tagliani (CAN) running
5. Oriol Servia (Esp) running
6. Timo Glock (Ger) running
7. Justin Wilson (GBR) running
8. Ronnie Bremer (Den) running
9. Ricardo Sperafico (Bra) running
10. Andrew Ranger (Can) running
Standings after 12 of 13 races:
1. Sebastien Bourdais (Fra) 344 pts
2. Oriol Servia (Esp) 266
3. Justin Wilson (GBR) 231