In late 2005 Power joined Champ Car Team Australia at the Lexmark Indy 300 event at Surfers Paradise in Australia, which also resulted in his departure from the World Series by Renault championship even though that season was still in progress and Power ultimately ended seventh in the championship. In the Indy 300 Power ran strongly until being knocked off the track by team mate Alex Tagliani. After the Surfers Paradise event he signed a multi-year contract to race for the team, which began immediately at the next Champ Car round in Mexico City after Tagliani's teammate Marcus Marshall was released for what was described as a "serious breach of contract".