Alexander Zverev had to come from two sets down and rising star Carlos Alcaraz also went the distance.
Emma Raducanu’s hopes of a deep run at Roland Garros were ended by the world number 47 Aliaksandra Sasnovich.
Her, the PA news agency looks back at day four at the French Open.
Picture of the day
Match of the day
Third seed Alexander Zverev found himself in the increasingly familiar position of trailing by two sets but battled back to beat Sebastian Baez of Argentina 2-6 4-6 6-1 6-2 7-5.
Shock of the day
Greek fourth seed Maria Sakkari came unstuck in two tie-breaks against world number 81 Karolina Muchova.
Djokovic and Nadal remain on course for a blockbuster meeting in the quarter-finals.
Defending champion Djokovic had few problems against Alex Molcan of Slovakia, the world number one winning 6-2 6-3 7-6 (4).
Then Nadal, the 13-time Roland Garros king, dispatched Frenchman Corentin Moutet 6-3 6-1 6-4 in the night match.
Women: Maria Sakkari (4), Emma Raducanu (12), Sorana Cirstea (26), Petra Kvitova (32).Menn: Taylor Fritz (13).
Emma Raducanu made an excellent start against Aliaksandra Sasnovich but the British number one ran out of steam, går ned 3-6 6-1 6-1. Cameron Norrie kept the British flag flying with a straight-sets win over Jason Kubler.
British number two Dan Evans will bid to reach the third round for the first time against Mikael Ymer of Sweden. The women take centre stage in the night match, with home hope Alize Cornet facing former champion Jelena Ostapenko.