Rafael Nadal and Stan Wawrinka both slumped to straight sets defeats in the third round of the Western and Southern Open in Cincinnati.
The Spaniard showed signs of fatigue after competing at the Rio Olympics as he was beaten 6-1 6-3 by Borna Coric, while Wawrinka’s error-strewn showing saw him lose 6-4 6-4 against Grigor Dimitrov.
Nadal, who was denied the bronze medal by a defeat to Kei Nishikori at the Rio Games, double faulted five times and ended with 27 unforced errors in a ragged performance.
Coric had previously beaten Nadal two years ago in Basel, at the age of just 17, and the talented Croatian repeated this feat to reach the quarter-finals of a Masters event for the first time.
Third seed Nadal was followed out of the tournament by the second seeded Wawrinka, who smashed his racket on the ground while dropping the first set.
The Swiss player committed two unforced errors at 3-3 in the second set, allowing Dimitrov to claim another decisive break.
Seventh seed Jo-Wilfried Tsonga also bowed out following a 6-3 7-6 defeat to Steve Johnson.