This rivalry is special, as Nadal and Djokovic have battled it out at all the 4 Grand Slam finals. They have played more than 40 matches against each other, and hold the record for the longest match in a Grand Slam final in the open era. While Djokovic has won 10 Grand Slams, Nadal is ahead with 14.
Though Serena Williams is considered to be one of the greatest tennis players, her sister is not too far behind. The rivalry between these siblings is as fierce as it gets, but off the court, they are as close as can be. They have met more than 25 times in their career, and have even played four consecutive Grand Slam finals. Serena has the better Grand Slam record at 21, while Venus stands at 7.