Pete Sampras, the third-ranked player in the world, was upset by Russian Andrei Cherkasov in the third round in Barcelona in 1992. The Barcelona Olympics were played on clay where the Sampras serve and volley style of play was really not deadly.
Sampras double-faulted to let Cherksasov go up 5-3 in the fifth set. The Russian served it out convincingly . Sampras lost 7-6, 6-1, 5-7, 0-6, 3-6. The last American male in singles tennis went home, whereas, Cherkasov lasted until the semifinals in 1992.
Cherkasov also beat second seed Stefan Edberg in the opening round, stealing the spot light at the Barcelona Olympics when it came to the underdogs.