The big Frenchman rallied from early deficits to extend semifinals against Novak Djokovic (French Open) and Andy Murray (Wimbledon) in his last two Grand Slam tournaments. And last month at the Olympics, Tsonga outlasted Milos Raonic in a three-set match that lasted an Olympic-record 66 games.
After dropping the opening set, Tsonga stormed back to take the second in convincing fashion. But his erratic play returned in the third and the 23-year-old Klizan took advantage.
Klizan, unseeded and ranked No. 52 in the world, had never advanced beyond the second round at a major.
In other Thursday action, 19-year-old American Jack Sock advanced to the third round with an impressive 6-2, 6-2, 6-4 win over Italian Flavio Cipolla. He’ll face Spaniard Nicolas Almagro, the No. 11 seed, who survived a five-setter against Philipp Petzschner of Germany, 6-3, 5-7, 5-7, 6-4, 6-4.