Japan's Kei Nishikori and Russia's Andrey Rublev on Monday successfully qualified for the Rolex Monte-Carlo Masters round of 32.
World No. 36 Nishikori upset world No. 18 Tomas Berdych of the Czech Republic 4-6, 6-2, 6-1 in a match that lasted one hour and 46 minutes.
This was Nishikori's third win against Berdych out of four career encounters.
World No. 33 Rublev triumphed over world No. 44 Robin Haase of the Netherlands 7-6 (7), 2-6, 7-5 in two hours and 30 minutes.
Nishikori, age 28, is set to play against Russia's Daniil Medvedev, world No. 49, in the next round.
Meanwhile, the 20-year-old Rublev moves on to face world No. 7 Dominic Thiem of Austria.