Novak Djokovic (SRB)  vs Rafael Nadal (ESP) . This was always viewed as the match that would determine who would win the tournament when the 2013 French Open draw was revealed two weeks ago. But both players had to get through their individual quarters of the draw to reach this stage, which they both did, both dispatching venerable opponents in straight sets in the quarters (Tommy Haas by Nole and Stanislas Wawrinka by Rafa). This is their 35th career meeting, with Nadal currently holding a 19-15 edge, but Djokovic won the last time they played, which was a rare win over the King of Clay in a clay court final, to wrest the Monte Carlo Masters shield from Nadal. It's hard to pick against Nadal here when he has only ever lost 1 match at Roland Garros and won the title a record 7 times. But he is playing someone who has beaten him 3 times in clay court finals and who very nearly beat him last year. One key factor will be the weather. The hotter and drier it is the better it is for Nadal because it helps him to use his excessive topspin on the ball to keep it out of Djokovic's strike zone. It was during heavy wet conditions last year in the 2012 final here that Djokovic reeled off a string of 7 games, something no one had ever done to Nadal. Nadal knows that Djokovic can beat him, and Djokovic knows that Nadal knows. In the end, this match up will most likely come down to mental tooughness, and there I give the slight edge to Nole. Mad Professah's pick: Djokovic.
David Ferrer (ESP)  vs Jo-Wilfried Tsonga (FRA)