Novak Djokovic hailed Rafael Nadal as a "great champion" after losing an epic late-night French Open quarter-final, but added he was "not surprised" by his rival's recovery from a debilitating injury. Nadal, the 13-time champion at Roland Garros, clinched a memorable 6-2, 4-6, 6-2, 7-6 (7/4) victory to reach his 15th semi-final at the tournament. For world number one Djokovic, defeat was his eighth in 10 meetings with Nadal at the French Open. "He was the better player in the important moments," said Djokovic. "He showed why he's a great champion. Staying there mentally tough and finishing the match the way he did. Congrats to him and his team. No doubt he deserved it."