Argentina’s Juan Martin Del Potro became the lowest ranked player since Jimmy Connors in 1991 to reach the quarter-finals of the US Open Tennis Championships at Flushing Meadows today, when his opponent, the 8th seed, Dominic Thiem from Austria retired with a knee injury during the second set of their match, with the score on 6-3 3-2 in Del Potro’s favour.

Del Potro will either meet Stanislas Wawrinka or Illya Marchenko, who are currently on court. Wawrinka has already taken the first two sets.