Powerscourt made amends for his demotion from first place in the Arlington Million 12 months ago with a brilliant victory in the Chicago showpiece last night.
Fallon was at his brilliant best on the Aidan O'Brien-trained five-year-old, who stormed to the front a furlong out and galloped on too strongly for the opposition.
Powerscourt did hang left towards the rail when taking the lead but not as badly as last year when, ridden by Jamie Spencer, he was relegated to fourth after causing interference.
The favourite Kitten's Joy was second with Fourty Niners Son third and Better Talk Now fourth.