Top seed Novak Djokovic continued his imperious progress at the French Open with a 6-0 6-3 6-2 drubbing of Colombian Daniel Galan to effortlessly reach the last 16 for the 11th straight year.

The 33-year-old was rarely extended by his 153rd-ranked opponent and even found time to double up as a court sweeper when the match was briefly interrupted by rain.

Djokovic, like 12-time champion Rafa Nadal, has reached the fourth round without the loss of a set although things will toughen up with powerful Russian Karen Khachanov up next.

The 33-year-old Serb won the first set in 28 minutes and when he broke for a 2-0 lead in the second set a rare 'triple bagel' looked a possibility.

But Galan, a lucky loser from qualifying, got on the board with a rasping forehand winner which brought loud cheers from the small crowd on Court Philippe Chatrier.

Galan playing in the rain as the roof shuts

With heavy rain falling and the new roof sliding slowly across, meaning Galan was exposed to the elements and Djokovic was not, the Serb ordered the chair umpire to halt play after his opponent slipped during a rally on the muddy baseline.

After groundsmen with wheelbarrows had spread more clay across the court to improve the slimy surface, a laughing Djokovic offered a hand, grabbing a sweeper, before resuming his day job with the roof closed.
Djokovic was surprised the roof had not been closed earlier.

"I saw the forecast and it didn't look good at all," he said. "If you have a roof why not use it. I thought we lost quite a bit of time."

He has certainly not been wasting any time so far in the French capital and once play resumed the outcome was never in doubt, although Galan did make the world number one work up a sweat with some courageous tennis of his own.

Djokovic, bidding for his second title at Roland Garros and 18th Grand Slam, saved four break points in a competitive third set before completing his 71st French Open match win, taking him past Roger Federer into second place behind Nadal who has 96. 

Greek fifth seed Stefanos Tsitsipas advanced to the fourth round of the French Open after his opponent Aljaz Bedene retired with an ankle injury while trailing 6-1 6-2 3-1.

Slovenian Bedene, who defeated Tsitsipas in straight sets when they met at Rotterdam earlier this year, first called for the physiotherapist on Court Suzanne Lenglen to get treatment on his right ankle after going down 5-0 in the opening set.

Tsitsipas congratulates Bedene after the latter withdraws himself

After returning to court Bedene won the first game to get on the scoreboard and then got his ankle strapped before the start of the second set.

Tsitsipas, the reigning ATP Finals champion, kept his focus and went about his business smoothly, hitting 28 winners and breaking the 56th-ranked Bedene's serve five times before the 31-year-old decided he could no longer continue.

In his fourth round, the Greek will play Bulgarian 18th seed Grigor Dimitrov, who also advanced in a similar fashion when Roberto Carballes Baena of Spain retired due to sickness after going down 6-1 6-3.

"I have been throwing up all the day," the Spaniard said. "I started yesterday night at 3am. I tried to warm up and tried to play, but I couldn't. It was impossible."

Pablo Carreno Busta won the all-Spanish battle against Davis Cup team mate Roberto Bautista Agut 6-4 6-3 5-7 6-4 to reach the fourth round for the second time.

Carreno Busta, seeded 17th, came into the match tied at 2-2 from previous meetings against 10th seed Bautista Agut but had won their most recent showdown at Rotterdam this year.

The US Open semi-finalist, who lost to German Alexander Zverev at Flushing Meadows, took the first two sets with a double break in each before Bautista Agut fought back to take the third.

Carreno Busta was down a break in the fourth set at 4-2 and the match seemed headed for a deciding set but he managed to raise his level and broke Bautista Agut in successive games to seal victory.

Carreno Busta served strongly and struck 65 winners to set up a clash with German qualifier Daniel Altmaier, ranked 186th, who beat Italian seventh seed Matteo Berrettini 6-2 7-6(5) 6-4.

Russian Andrey Rublev strolled into the last-16 with a facile 6-3 6-2 6-3 win over South African Kevin Anderson, extending his winning run on clay to eights matches.

He was joined by compatriot Karen Khachanov after the 15th seed ousted Chile's Cristian Garin 6-2 3-6 6-4 6-2 to reach the round four in as many appearances at Roland Garros.

"Good to keep doing the consistency here in Paris," said Khachanov, who faces Serbian top seed Novak Djokovic next.

"Whenever I come here I feel good, feeling that I need to work on the points, on the matches, just trying to be positive match-by-match. It feels good to be in the second week of a slam this year."

Rublev, 22, only lost four points on his first serve and broke Anderson's serve once in the opening set and twice each in the next two to complete the victory in one hour 34 minutes.

In his first appearance in the fourth round in Paris, former junior world number one Rublev will play Hungarian Marton Fucsovics, who beat Thiago Monteiro of Brazil 7-5 6-1 6-3.