Murray, who has never won the clay court Grand Slam, won an 84-minute opening set after clinching a tiebreak 10-8.

The double Olympic champion then went on to claim the second and third sets 7-5 and 6-0 respectively to secure victory over Del Potro, who he beat in the final of Rio 2016.

"The first set was very, very important for me - in these conditions, slowing and heavy, to come back would have been difficult if I had lost it," two-time Wimbledon champion Murray said after the match.

"I'm starting to feel better.

"I was looking forward to Roland Garros, I've struggled the last six, seven weeks coming in but I have great memories here and hopefully I can now keep it going."

Awaiting in the next round for Murray, who lost in the final to Novak Djokovic of Serbia at last year's French Open, will be American John Isner or Russia's Karen Khachanov.

Their match will conclude tomorrow after rain in Paris delayed this evening's play.

The Russian took the first set 7-6 before the rain came.

British number two Kyle Edmund was beaten by Kevin Anderson in five sets.

The South African came from behind to win 6-7, 7-6, 5-7, 6-1, 6-4 in an epic match lasting four hours.

Switzerland's third seed Stan Wawrinka progressed after claiming a 7-6, 6-0, 6-2 win over Italy's Fabio Fognini.

Pablo Cuevas, who was bidding to become the first Uruguayan to reach the round of 16 at a Grand Slam in 18 years, was comfortably beaten 6-2, 6-1, 6-3 by Spain's Fernando Verdasco.

Croatian seventh seed Marin Cilic also advanced after sweeping aside Spain's Feliciano Lopez 6-1, 6-3, 6-3 to reach the last 16 without dropping a set.

In the women's event, Romania's Simona Halep sealed her place in the fourth round with a 6-0, 7-5 win over Russia's Daria Kasatkina.

Halep is in sublime form after winning the Madrid Open and reaching the final in Rome last month, and is one of the favourites in Paris as a result.

She will now face Spain's Carla Suarez Navarro for a place in the quarter-finals after the number 21 seed claimed a 6-4, 6-4 win over Elena Vesnina of Russia.

Elsewhere, ninth seed Agnieszka Radwanska of Poland was stunned 6-2, 6-1 by France's Alize Cornet.

Cornet will now meet her compatriot Caroline Garcia in the last 16.

Garcia overcame Taiwan's Hsieh Su-wei 6-4, 4-6, 9-7.

Following Kristina Mladenovic's victory yesterday there are now three French women in the last 16 of a Grand Slam for the first time since the 2008 US Open.

Denmark's Caroline Wozniacki resumed her match against 18-year-old American Catherine Bellis after rain stopped play yesterday night.

The former world number one went on to complete a 6-2, 2-6, 6-3 win.