Novak Djokovic took his unbeaten record in 2011 to 38 wins on Monday before Grand Slam king Roger Federer demonstrated to the unstoppable Serb that he is still a French Open force. World number one Caroline Wozniacki showed no respect for her elders on Monday, crushing Japan's Kimiko Date-Krumm - a woman twice her age - 6-0, 6-2 in the first round.