Second seed Daniil Medvedev moved into the third round of the French Open by beating Serbia's Laslo Djere.
The 26-year-old US Open champion gained a routine 6-3 6-4 6-3 victory in Thursday's opening match on Court Philippe Chatrier.
The Russian will face Serbia's 28th seed Miomir Kecmanovic, who won in four sets against Alexander Bublik.
"It was a very tough match but I'm happy to win. I have a lot more to do to be remembered," Medvedev said.
"Laslo was playing a bit better clay-court tennis but I managed to fight to put one more ball in."
Medvedev, who had a hernia operation in April, has now won both of his matches in three sets after beating Argentina's Facundo Bagnis 6-2 6-2 6-2 in the first round.
Medvedev, competing under a neutral flag in Paris, is one of the players who will not be allowed to compete at Wimbledon this year after Russian and Belarusian players were banned following Russia's invasion of Ukraine.
Tsitsipas forced to dig deep
Last year's finalist Stefanos Tsitsipas of Greece was pushed hard by Czech qualifier Zdenek Kolar before eventually prevailing 6-3 7-6 (10-8) 6-7 (3-7) 7-6 (9-7).
Tsitsipas had to come through a gruelling five-set match in the opening round against Lorenzo Musetti and this was another tough test for the world number four.
He was 6-2 down in the fourth set tie-break but hit three forehand winners in a row before going on to secure the victory in four hours and six minutes.
Kolar's efforts received a standing ovation from the crowd and Tsitsipas, 23, said: "He drove me crazy!
"It was really frustrating, he was behind every ball, it was not easy. He was putting every part of his body behind the ball and I want to congratulate him for an incredible effort."
Tsitsipas will next face Sweden's Mikael Ymer, who beat Great Britain's Dan Evans, for a place in the last 16.
Simon marches on in Paris farewell
France's Gilles Simon prolonged his Roland Garros farewell as he beat American Steve Johnson 7-5 6-1 7-6 (8-6) to reach the third round.
The 37-year-old is playing in his final French Open and became the third Frenchman in the Open Era to record 500 wins after Richard Gasquet (574) and Gael Monfils (523).
Elsewhere, Belgium's David Goffin fought back to beat American 24th seed Frances Tiafoe 3-6 7-6 (7-1) 6-2 6-4 and reach the third round of the French Open for the first time since 2019.
Finally, France's Hugo Gaston also progressed as he defeated Pedro Cachin 6-4 6-2 6-4, while seventh seed Andrey Rublev overcame Argentina's Federico Delbonis 6-3 3-6 6-2 6-3 and Italian Jannik Sinner, the 11th seed, came back from a set down to beat Spaniard Roberto Carballes Baena 3-6 6-4 6-4 6-3.