Before Simona Halep v Garbiñe Muguruza and Madison Keys v Sloane Stephens, there's the not-so-small matter of Rafael Nadal's quarter-final against Diego Schwartzman, plus Marin Cilic v Juan Martín del Potro.
The first set finished 6-4 in Schwartzman's favour, whilst play ended for the day with the Spaniard leading 5-3 in the second set, serving for the set when play resumes. Nadal was nowhere near his best tennis, having to play against four break points in the very first game and suffering three breaks of serve. In a match that had several tie-breaks written all over it, the pair were duking it out in a ... tie-break, with the score locked at 5-5 when they were forced off court.
A rescued break point in the opening game of the third was further evidence of Marterer's fortitude and Nadal was guilty of losing focus, smashing a routine forehand into the tramlines to go 3-1 down.
The 10-time Roland Garros champion was a break down at 3-2 in the second when the weather halted Schwartzman's momentum and Nadal returned from the interval with a spring in his step to take a 5-3 lead. World number one Nadal, who made 14 unforced errors and struck just four winners in the opener, has only lost two French Open matches in his career.
However, when the players came back on after a delay of nearly an hour Nadal immediately broke back to level the second set.
Schwartzman's supporters will be hoping he won't be too exhausted from his heroic five-set win over the giant South African Kevin Anderson on Monday and has the self-belief to overcome a 0-5 head-to-head record against Nadal.
Her semi-final with Halep will also decide the world number one spot next week.
From the moment Nadal took the second set, it looked unlikely Schwartzman would earn a first win in six attempts against the man at whose academy he had previously trained.