World number one Iga Swiatek racked up her 31st straight win to reach the French Open last 16 on Saturday as Daniil Medvedev and Stefanos Tsitsipas looked to make the second week and pounce on any slip-up by title favourites Novak Djokovic and Rafael Nadal.
Swiatek, the 2020 champion in Paris, dropped serve three times against 95th-ranked Danka Kovinic of Montenegro before sealing a 6-3, 7-5 victory.
Kovinic recovered from 1-4 down in the second set to lead 5-4 but the Pole steadied with a hold and a break before serving out for victory.
Swiatek will next face either Chinese teenager Zheng Qinwen, making her debut in Paris, or France's Alize Cornet, playing in her 61st consecutive Grand Slam.
"I wanted to play really aggressively but sometimes I felt I was hitting with too much power and it was hard to control," said Swiatek.
"I needed to play with a little less risk and be more consistent. She did a pretty good job of defending and giving back at full speed."
Swiatek's winning streak is the best on tour since Serena Williams's run of 34 successive victories in 2013.
11 set points wasted
In early action, Mackenzie McDonald, the 60th-ranked American, slipped to defeat to Italian 11th seed Jannik Sinner after managing to squander 11 set points in the second set.
Sinner, a quarter-finalist in 2020, triumphed 6-3, 7-6 (8/6), 6-3 and will face seventh-seeded Andrey Rublev for a last eight spot.
"I am not 100 percent but I found a solution," said the 20-year-old Sinner who played with strapping below his left knee.
Rublev, also a quarter-finalist two years ago, defeated Chile's Cristian Garin 6-4, 3-6, 6-2, 7-6 (13/11).
Garin saved three match points in the fourth set while Rublev saved five set points in the tiebreak.
Leolia Jeanjean's run ended when the 227th-ranked wildcard was defeated 6-1, 6-4 by Irina-Camelia Begu of Romania.
Jeanjean, once one of France's greatest hopes before her career was derailed by a succession of knee injuries, had knocked out former world number one Karolina Pliskova in the second round.
'Shaking a little'
"In the end, I was shaking a little bit," admitted 63rd-ranked Begu who is in the fourth round for the first time since 2016.
Begu goes on to face either 2021 semi-finalist Tamara Zidansek of Slovenia or US 11th seed Jessica Pegula for a place in the quarter-finals.
Later Saturday, world number two Medvedev and 2021 runner-up Tsitsipas, who are seeded to meet in the semi-finals, also target the last 16.
So far, Medvedev has looked the most likely to reach that stage, dropping just 16 games in two straight-sets wins.
Fourth-ranked Tsitsipas, however, had to come back from two sets down to beat Italy's Lorenzo Musetti in the first round.
Then he needed four hours and four sets to see off 134th-ranked qualifier Zdenek Kolar.
Medvedev, a quarter-finalist at Roland Garros last year after four successive first round exits, takes on 28th seed Miomir Kecmanovic.
The 22-year-old Serb has had a solid clay season with a semi-final run in Munich and a quarter-final spot in Belgrade where he took Novak Djokovic to three sets. He also made the last eight in Rio and Santiago.
Tsitsipas faces unseeded Mikael Ymer of Sweden, the world number 95 who arrived at the tournament on a seven-match losing streak, stretching back to a semi-final defeat to Alexander Zverev in Montpellier in February.
However, Ymer has rediscovered his form in Paris, reaching the third round for a second successive season.
The third round also throws up two battles of tennis past and tennis future.
Holger Rune, just 19, faces 21-year-old Hugo Gaston. In stark contrast, 37-year-old Gilles Simon of France, playing on the tour for the final year, meets former US Open champion Marin Cilic, 33.
Now ranked 158, Simon, a former sixth-ranked player, has made the fourth round on three occasions having made his debut in 2005.
He enjoys a career edge of 6-1 over 23rd-ranked Cilic with their first meeting having taken place at Wimbledon in 2007.
Women's third seeded Paula Badosa, who made the quarter-finals in 2021, is up against Russian 29th seed Veronika Kudermetova.
Badosa has won both the pair's meetings this year, including on the Madrid clay for the loss of just three games.