Australia's championship leader Will Power has history against him at Indycar's Road America race in Wilsconsin as Alexander Rossi claimed his first pole in three years.

Power, who went back to the top of the standings with victory in Detroit last week, failed to advance out of the first group in qualifying on Saturday and will start from 15th on the grid.

IndyCar has never had a winner come from farther back than 13th, done by Alex Tagliani in 2004.

American Rossi will start from the pole at Road America, the site of his last IndyCar Series victory 44 races ago on June 23, 2019.

"It's pretty crazy to just think it's been so long," Rossi said.

Rossi turned a lap in Saturday qualifying of 1 minute, 44.8656 seconds on the 14-turn, 4.048-mile permanent road course considered one of the best in the world.

His lap put the Andretti Autosport driver on pole for the first time since Belle Isle in 2019, three weeks before his last win.

"It's been a long time since we've been in this position," Rossi said. "It's amazing. It's cool. We'll enjoy it, but we've got a job to do."

The American became the eighth different pole winner through eight qualifying sessions, the most parity since 1961 for IndyCar. There were nine different pole winners that season.

Josef Newgarden of Team Penske qualified second and was followed by Chip Ganassi Racing teammates Alex Palou, the reigning series champion, and Marcus Ericsson, the Indianapolis 500 winner.

Colton Herta of Andretti was fifth to give Honda four drivers in the top five, while Pato O'Ward of Arrow McLaren SP joined Newgarden as the only Chevrolet entries to advance to the Fast Six round of qualifying.

Simona de Silvestro, making her first start of the season, qualified 27th and last in the field as she adapts to her first IndyCar road course race since 2015. She and Tatiana Calderon give IndyCar a pair of women in the same race for the first time since the 2013 season finale.

Rossi, meanwhile, has been a roll the last three weeks.

He finished fifth in the Indianapolis 500 and was runner-up to Power last week in Detroit. He also confirmed last week he's leaving Andretti Autosport at the end of his seventh season to drive for McLaren next year.

"I don't think there's any revelation. We're not doing anything different," Rossi said. "Mistakes are minimised, chaotic events, minus a clutch blowing up this morning, have been relatively under control."