Nov 14 (Reuters) - When Carlos Alcaraz beat Novak Djokovic to win Wimbledon in July it seemed the Spaniard's stratospheric career trajectory was limitless and he would take a stranglehold on men's tennis. A few months later, however, 24-time Grand Slam champion Djokovic has re-asserted his authority and Alcaraz is experiencing the first slump of his career. The 20-year-old bemoaned the fast playing conditions in Turin after a surprise loss to Germany's Alexander Zverev in his opening match at the ATP Finals on Monday. Daniil Medvedev, whose defeat of Alcaraz in the U.S. Open semi-final exposed some cracks in the Spaniard's game, says that a dip was to be expected at some point. Alcaraz will face Rublev in Red Group on Wednesday when defeat could end his hopes of reaching the semi-finals.

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Persons: Carlos Alcaraz, Novak Djokovic, Djokovic, Germany's Alexander Zverev, Daniil Medvedev, Andrey Rublev, Carlos, Novak, Pete Sampras, Alex Corretja, Carlitos, Martyn Herman, Pritha Sarkar Organizations: Wimbledon, ATP, U.S, Red Group, Eurosport, Thomson Locations: Turin, Alcaraz, Russian