Juan Martin del Potro has been defeated by Horacio Zeballos in the second round of the Miami Masters after his Argentine compatriot had earlier replaced Roger Federer.
The world number three withdrew from the event with a stomach virus, gifting Zeballos a lucky-loser spot and a chance to play Del Potro on the show court in Florida.
Del Potro, a former US Open champion, started as favourite but he failed to create a single break point as Zeballos ran out a 6-4 6-4 winner.
Despite finishing the match, the 27-year-old will likely be more concerned with his troublesome wrist after receiving treatment during the contest.
