Novak Djokovic demolished Colombian lucky loser Daniel Galan to reach the Roland Garros last 16 for a record-equalling 11th successive year on Saturday as unheralded Daniel Altmaier struck another blow for the underdogs.

The women's draw also had a new look ahead of the second week with only five of the top 20 seeds reaching the fourth round.

World number one Djokovic swept past 153rd-ranked Galan 6-0, 6-3, 6-2, his most challenging moment coming when he helped ground staff lay more clay on the surface of Court Philippe Chatrier after rain had made it treacherous.

"I played pretty solid today, I'm happy about that," said Djokovic, the 2016 champion who is chasing an 18th Grand Slam title, after his 71st win in Paris.

Djokovic, who has dropped just 15 games in three rounds, took his 2020 record to 34 wins against one loss as he continues his bid to become the first man in half a century to win all four Grand Slam titles twice.

Next up is Russian 15th seed Karen Khachanov who put out Chile's Cristian Garin.

The day after world number 239 Hugo Gaston and Sebastian Korda, ranked at 213, made the last 16, German qualifier Altmaier kept the sport's outsiders in the headlines.

The world number 186 stunned seventh seed Matteo Berrettini of Italy 6-2, 7-6 (7/5), 6-4, becoming just the fourth man in 20 years to reach the round of 16 on his Grand Slam debut.

Victory also means an unexpected financial windfall for the 22-year-old who is guaranteed at least $221,400 having earned $173,600 in his entire six-year career.

Altmaier paid tribute to three-time major winner Stan Wawrinka for his help when he missed virtually all of 2018 through injury.

"When I was watching him, he always says 'Allez, Stan.' I copy him a little bit because I like to say, 'Allez, Dan'. He has been a huge reason why I'm healthy now."

Arab landmark for Jabeur

Greek fifth seed Stefanos Tsitsipas made the fourth round for a second successive year when Slovenia's Aljaz Bedene retired with a right foot injury.

The 22-year-old was on court for just 80 minutes and was leading 6-1, 6-2, 3-1 when Bedene called it quits.

Next up for Tsitsipas is Bulgarian 18th seed Grigor Dimitrov who also profitted from a retirement with Roberto Carballes Baena 6-1, 6-3 down when he gave up due to illness.

The Spaniard had shocked ninth seed Denis Shapovalov in the previous round but that five-hour epic came back to haunt him.

Russian 13th seed Andrey Rublev, the champion on clay in Hamburg on the eve of Roland Garros, eased past veteran South African Kevin Anderson in just 94 minutes.

Rublev didn't face a break point in his 6-3, 6-2, 6-3 win as he moved into the last 16 for the first time where he will face world number 63 Marton Fucsovics, the first Hungarian man in the second week since Balazs Taroczy in 1984.

Tunisia's Ons Jabeur became the first Arab woman to make the last 16 with a 7-6 (9/7), 2-6, 6-3 win over Belarusian eighth seed Aryna Sabalenka.

Jabeur, seeded 30, who made the quarter-finals at the Australian Open in January, next faces 57th-ranked American Danielle Collins who stunned 2016 champion and 11th seed Garbine Muguruza 7-5, 2-6, 6-4.

"The people in Tunisia are really encouraging me a lot. Media, I'm not sure," said Jabeur.

American fourth seed and Australian Open champion Sofia Kenin eased through with a 6-2, 6-0 defeat of Romanian qualifier Irina Bara.

Kenin, who defeated Serena Williams in the fourth round last year, will face unseeded French player Fiona Ferro.

Zhang Shuai became the first Chinese woman to reach the last 16 since former champion Li Na in 2012.

Zhang, 31, defeated French wildcard, and world number 357, Clara Burel 7-6 (7/2), 7-5 and will next face seventh seed Petra Kvitova who came back from 1-5 down in the first set and saved two set points to see off 18-year-old Canadian Leylah Fernandez 7-5, 6-3.

Spain's Paula Badosa, ranked at 87, wept in her courtside chair as she reached the round of 16 at a Slam for the first time.

The 2015 junior champion, who put out former US Open winner Sloane Stephens in the last round, defeated 2017 champion in Paris Jelena Ostapenko 6-4, 6-3.

Ostapenko was undone by 43 unforced errors and 10 double faults.

#Ons Jabeur

Djokovic into Roland Garros last 16 as women seeds scattered