Sixth seed Juan Martin Del Potro of Argentina roared into his second grand slam semi-final of the year with a 4 set victory victory over Croatian 16th seed Marin Cilic at the U.S. Open in New York.
After winning the first set and holding a 3-1 lead in the second, Cilic started spraying his groundstrokes and the demoralised Croat lost 17 of the final 20 games of the match.
Cilic had 53 unforced errors, compared to just 24 for Del Potro.
The Argentine, one of the tour's hottest players, converted all eight of his break-point opportunities.
Del Potro, who reached the last four at the French Open, will face the winner of the match later today between third seed Rafael Nadal and number 11 Fernando Gonzalez.
Five-times champion Roger Federer and fourth seed Novak Djokovic will contest the other semi-final of the year's final grand slam tournament.