It's better to look at their match records:
Roger Federer
1999 French Open
R128: Patrick Rafter def. Roger Federer (5-7, 6-3, 6-0, 6-2)
2000 French Open
R128: Roger Federer def. Wayne Arthurs (7-6, 6-3, 1-6, 6-3)
R64: Roger Federer def. Jan-Michael Gambill (7-6, 6-3, 6-3)
R32: Roger Federer def. Michel Kratochvil (7-6, 6-4, 2-6, 6-7, 8-6)
R16: Alex Corretja def. Roger Federer (7-5, 7-6, 6-2)
2001 French Open
R128: Roger Federer def. Stefano Galvani (6-3, 6-3, 6-3)
R64: Roger Federer def. Sargis Sargsian (4-6, 3-6, 6-2, 6-4, 9-7)
R32: Roger Federer def. David Sanchez (6-4, 6-3, 1-6, 6-3)
R16: Roger Federer def. Wayne Arthurs (3-6, 6-3, 6-4, 6-2)
QF: Alex Corretja def. Roger Federer (7-5, 6-4, 7-5)
2002 French Open
R128: Hicham Arazi def. Roger Federer (6-3, 6-2, 6-4)
2003 French Open
R128: Luis Horna def. Roger Federer (7-6, 6-2, 7-6)
2004 French Open
R128: Roger Federer def. Kristof Vliegen (6-1, 6-2, 6-1)
R64: Roger Federer def. Nicolas Kiefer (6-3, 6-4, 7-6)
R32: Gustavo Kuerten def. Roger Federer (6-4, 6-4, 6-4)
2005 French Open
R128: Roger Federer def. Dudi Sela (6-1, 6-4, 6-0)
R64: Roger Federer def. Nicolas Almagro (6-3, 7-6, 6-2)
R32: Roger Federer def. Fernando Gonzalez (7-6, 7-5, 6-2)
R16: Roger Federer def. Carlos Moya (6-1, 6-4, 6-3)
QF: Roger Federer def. Victor Hanescu (6-2, 7-6, 6-3)
SF: Rafael Nadal def. Roger Federer (6-3, 4-6, 6-4, 6-3)
2006 French Open
R128: Roger Federer def. Diego Hartfield (7-5, 7-6, 6-2)
R64: Roger Federer def. Alejandro Falla (6-1, 6-4, 6-3)
R32: Roger Federer def. Nicolas Massu (6-1, 6-2, 6-7, 7-5)
R16: Roger Federer def. Tomas Berdych (6-3, 6-2, 6-3)
QF: Roger Federer def. Mario Ancic (6-4, 6-3, 6-4)
SF: Roger Federer def. David Nalbandian (3-6, 6-4, 5-2 ret.)
F: Rafael Nadal def. Roger Federer (1-6, 6-1, 6-4, 7-6)
2007 French Open
R128: Roger Federer def. Michael Russell (6-4, 6-2, 6-4)
R64: Roger Federer def. Thierry Ascione (6-1, 6-2, 7-6)
R32: Roger Federer def. Potito Starace (6-2, 6-3, 6-0)
R16: Roger Federer def. Mikhail Youzhny (7-6, 6-4, 6-4)
QF: Roger Federer def. Tommy Robredo (7-5, 1-6, 6-1, 6-2)
SF: Roger Federer def. Nikolay Davydenko (7-5, 7-6, 7-6)
F: Rafael Nadal def. Roger Federer (6-3, 4-6, 6-3, 6-4)
2008 French Open
R128: Roger Federer def. Sam Querrey (6-4, 6-4, 6-3)
R64: Roger Federer def. Albert Montanes (6-7, 6-1, 6-0, 6-4)
R32: Roger Federer def. Mario Ancic (6-3, 6-4, 6-2)
R16: Roger Federer def. Julien Benneteau (6-4, 7-5, 7-5)
QF: Roger Federer def. Fernando Gonzalez (2-6, 6-2, 6-3, 6-4)
SF: Roger Federer def. Gael Monfils (6-2, 5-7, 6-3, 7-5)
F: Rafael Nadal def. Roger Federer (6-1, 6-3, 6-0)
2009 French Open
R128: Roger Federer def. Alberto Martin (6-4, 6-3, 6-2)
R64: Roger Federer def. Jose Acasuso (7-6, 5-7, 7-6, 6-2)
R32: Roger Federer def. Paul-Henri Mathieu (4-6, 6-1, 6-4, 6-4)
R16: Roger Federer def. Tommy Haas (6-7, 5-7, 6-4, 6-0, 6-2)
QF: Roger Federer def. Gael Monfils (7-6, 6-2, 6-4)
SF: Roger Federer def. Juan Martin del Potro (3-6, 7-6, 2-6, 6-1, 6-4)
F: Roger Federer def. Robin Soderling (6-1, 7-6, 6-4)
2010 French Open
R128: Roger Federer def. Peter Luczak (6-4, 6-1, 6-2)
R64: Roger Federer def. Alejandro Falla (7-6, 6-2, 6-4)
R32: Roger Federer def. Julian Reister (6-4, 6-0, 6-4)
R16: Roger Federer def. Stanislas Wawrinka (6-3, 7-6, 6-2)
QF: Robin Soderling def. Roger Federer (3-6, 6-3, 7-5, 6-4)
2011 French Open
R128: Roger Federer def. Feliciano Lopez (6-3, 6-4, 7-6)
R64: Roger Federer def. Maxime Teixeira (6-3, 6-0, 6-2)
R32: Roger Federer def. Janko Tipsarevic (6-1, 6-4, 6-3)
R16: Roger Federer def. Stanislas Wawrinka (6-3, 6-2, 7-5)
QF: Roger Federer def. Gael Monfils (6-4, 6-3, 7-6)
SF: Roger Federer def. Novak Djokovic (7-6, 6-3, 3-6, 7-6)
F: Rafael Nadal def. Roger Federer (7-5, 7-6, 5-7, 6-1)
2012 French Open
R128: Roger Federer def. Tobias Kamke (6-2, 7-5, 6-3)
R64: Roger Federer def. Adrian Ungur (6-3, 6-2, 6-7, 6-3)
R32: Roger Federer def. Nicolas Mahut (6-3, 4-6, 6-2, 7-5)
R16: Roger Federer def. David Goffin (5-7, 7-5, 6-2, 6-4)
QF: Roger Federer def. Juan Martin del Potro (3-6, 6-7, 6-2, 6-0, 6-3)
SF: Novak Djokovic def. Roger Federer (6-4, 7-5, 6-3)
2013 French Open
R128: Roger Federer def. Pablo Carreno-Busta (6-2, 6-2, 6-3)
R64: Roger Federer def. Somdev Devvarman (6-2, 6-1, 6-1)
R32: Roger Federer def. Julien Benneteau (6-3, 6-4, 7-5)
R16: Roger Federer def. Gilles Simon (6-1, 4-6, 2-6, 6-2, 6-3)
QF: Jo-Wilfried Tsonga def. Roger Federer (7-5, 6-3, 6-3)
Rafael Nadal
2005 French Open
R128: Rafael Nadal def. Lars Burgsmuller (6-1, 7-6, 6-1)
R64: Rafael Nadal def. Xavier Malisse (6-2, 6-2, 6-4)
R32: Rafael Nadal def. Richard Gasquet (6-4, 6-3, 6-2)
R16: Rafael Nadal def. Sebastien Grosjean (6-4, 3-6, 6-0, 6-3)
QF: Rafael Nadal def. David Ferrer (7-5, 6-2, 6-0)
SF: Rafael Nadal def. Roger Federer (6-3, 4-6, 6-4, 6-3)
FR: Rafael Nadal def. Mariano Puerta (6-7, 6-3, 6-1, 7-5)
2006 French Open
R128: Rafael Nadal def. Robin Soderling (6-2, 7-5, 6-1)
R64: Rafael Nadal def. Kevin Kim (6-2, 6-1, 6-4)
R32: Rafael Nadal def. Paul-Henri Mathieu (5-7, 6-4, 6-4, 6-4)
R16: Rafael Nadal def. Lleyton Hewitt (6-2, 5-7, 6-4, 6-2)
QF: Rafael Nadal def. Novak Djokovic (6-4, 6-4 ret.)
SF: Rafael Nadal def. Ivan Ljubicic (6-4, 6-2, 7-6)
FR: Rafael Nadal def. Roger Federer (1-6, 6-1, 6-4, 7-6)
2007 French Open
R128: Rafael Nadal def. Juan Martin del Potro (7-5, 6-3, 6-2)
R64: Rafael Nadal def. Flavio Cipolla (6-2, 6-1, 6-4)
R32: Rafael Nadal def. Albert Montanes (6-1, 6-3, 6-2)
R16: Rafael Nadal def. Lleyton Hewitt (6-3, 6-1, 7-6)
QF: Rafael Nadal def. Carlos Moya (6-4, 6-3, 6-0)
SF: Rafael Nadal def. Novak Djokovic (7-5, 6-4, 6-2)
FR: Rafael Nadal def. Roger Federer (6-3, 4-6, 6-3, 6-4)
2008 French Open
R128: Rafael Nadal def. Thomaz Bellucci (7-5, 6-3, 6-1)
R64: Rafael Nadal def. Nicolas Devilder (6-4, 6-0, 6-1)
R32: Rafael Nadal def. Jarkko Nieminen (6-1, 6-3, 6-1)
R16: Rafael Nadal def. Fernando Verdasco (6-1, 6-0, 6-2)
QF: Rafael Nadal def. Nicolas Almagro (6-1, 6-1, 6-1)
SF: Rafael Nadal def. Novak Djokovic (6-4, 6-2, 7-6)
FR: Rafael Nadal def. Roger Federer (6-1, 6-3, 6-0)
2009 French Open
R128: Rafael Nadal def. Marcos Daniel (7-5, 6-4, 6-3)
R64: Rafael Nadal def. Teymuraz Gabashvili (6-1, 6-4, 6-2)
R32: Rafael Nadal def. Lleyton Hewitt (6-1, 6-3, 6-1)
R16: Robin Soderling def. Rafael Nadal (6-2, 6-7, 6-4, 7-6)
2010 French Open
R128: Rafael Nadal def. Gianni Mina (6-2, 6-2, 6-2)
R64: Rafael Nadal def. Horacio Zeballos (6-2, 6-2, 6-3)
R32: Rafael Nadal def. Lleyton Hewitt (6-3, 6-4, 6-3)
R16: Rafael Nadal def. Thomaz Bellucci (6-2, 7-5, 6-4)
QF: Rafael Nadal def. Nicolas Almagro (7-6, 7-6, 6-4)
SF: Rafael Nadal def. Jurgen Melzer (6-2, 6-3, 7-6)
FR: Rafael Nadal def. Robin Soderling (6-4, 6-2, 6-4)
2011 French Open
R128: Rafael Nadal def. John Isner (6-4, 6-7, 6-7, 6-2, 6-4)
R64: Rafael Nadal def. Pablo Andujar (7-5, 6-3, 7-6)
R32: Rafael Nadal def. Antonio Veic (6-1, 6-3, 6-0)
R16: Rafael Nadal def. Ivan Ljubicic (7-5, 6-3, 6-3)
QF: Rafael Nadal def. Robin Soderling (6-4, 6-1, 7-6)
SF: Rafael Nadal def. Andy Murray (6-4, 7-5, 6-4)
FR: Rafael Nadal def. Roger Federer (7-5, 7-6, 5-7, 6-1)
2012 French Open
R128: Rafael Nadal def. Simone Bolelli (6-2, 6-2, 6-1)
R64: Rafael Nadal def. Denis Istomin (6-2, 6-2, 6-0)
R32: Rafael Nadal def. Eduardo Schwank (6-1, 6-3, 6-4)
R16: Rafael Nadal def. Juan Monaco (6-2, 6-0, 6-0)
QF: Rafael Nadal def. Nicolas Almagro (7-6, 6-2, 6-3)
SF: Rafael Nadal def. David Ferrer (6-2, 6-2, 6-1)
FR: Rafael Nadal def. Novak Djokovic (6-4, 6-3, 2-6, 7-5)
2013 French Open
R128: Rafael Nadal def. Daniel Brands (4-6, 7-6, 6-4, 6-3)
R64: Rafael Nadal def. Martin Klizan (4-6, 6-3, 6-3, 6-3)
R32: Rafael Nadal def. Fabio Fognini (7-6, 6-4, 6-4)
R16: Rafael Nadal def. Kei Nishikori (6-4, 6-1, 6-3)
QF: Rafael Nadal def. Stanislas Wawrinka (6-2, 6-3, 6-1)
SF: Rafael Nadal def. Novak Djokovic (6-4, 3-6, 6-1, 6-7, 9-7)
FR: Rafael Nadal def. David Ferrer (6-3, 6-2, 6-3)