Rafael Nadal takes the first step towards what he hopes will be a third consecutive French Open crown when he plays Juan Martin del Potro of Argentina in the first round on Tuesday.
The Spanish second seed, who is bidding to join Swede Bjorn Borg in winning three Roland Garros titles in a row, is also chasing his third grand slam crown.
Del Potro will be no pushover, however.
The 18-year-old is an emerging talent on the men's tour, having become the youngest player to finish a year inside the top 100 of the world rankings when he ended 2006 at 91st.
Nadal, whose record run of consecutive wins on clay was ended at 81 by world number one Roger Federer in the final of the Hamburg Masters earlier this month, beat Del Potro 6-0 6-4 in their only previous meeting, in Miami in March.
Top seed Federer, bidding to complete a full set of grand slam titles, resumes his rain-interrupted first-round match.
The Swiss, who holds the Wimbledon, US Open and Australian Open titles, leads American Michael Russell 6-4 4-1.
Serbian Novak Djokovic, the sixth seed who is tipped as a contender for the title, opens his campaign against Santiago Giraldo of Colombia.
In the women's event, fourth seed Jelena Jankovic takes on Stephanie Foretz of France, while sixth seed Nicole Vaidisova, a semi-finalist last year, meets Emmanuelle Gagliardi of Switzerland.
Only 14 matches have been completed after two days of the Open because of rain and organisers will be hoping for better weather to help clear the backlog.