Del Potro accounted for the Swiss maestro in four sets (7-5 3-6 7-6 6-4) after Federer fought back to claim the second set.

The 36-year-old needed five sets to beat the unseeded pair of Frances Tiafoe and Mikhail Youzhny in the tournament’s first and second rounds, respectively.

His eviction ends hope of a semi-final match-up against Rafael Nadal.