Complex sentence: Korolev then played his first master series event in Indian Wells to which he was eliminated by Novak Djokovic in straight sets, however described it has a learning curve after wins over Simon Gruel and close friend Dmitry Tursunov.
Split into simpler sentences: Korolev then played his first masters series event in Indian Wells, in which he was eliminated by Novak Djokovic in straight sets. He later described this as a learning curve, after wins over Simon Gruel and close friend Dmitry Tursunov.