Andy Murray posts a reminder of his toughness in Paris

Andy Murray posts a reminder of his toughness in Paris

In fact this was his first ever straight sets win against Del Potro, against whom he fought out an epic Rio Olympics final and then lost to in September's pivotal Davis Cup semi-final rubber.

The world number one has been searching for top form all season and finally found something close to it on a cool, grey day at Roland Garros. Murray jogged to his seat at the changeover, the Argentine stood at the net, bent at the waist, his head resting on the net cord. Del Potro rallied to restore parity at 6-6 and earned another set point with a reflex forehand victor. After losing to Murray in the first round, Del Potro showed a moment of emotion as he smacked his racquet angrily and slumped on the net before resuming the second round. "I think we are going to see a lot more of her", Wozniacki said.

Another set point was saved and then Murray, whose drop shots were masterful, extracted the forehand error at 9-8, which went wide by millimetres.

Anderson, who conquered Australia's Nick Kyrgios in the second round advanced to the fourth round with a five-set win over Briton Kyle Edmund.

3 - times Simona Halep has now made the Roland Garros fourth round in eight appearances.

A remarkable effort saw Del Potro break back for 5-5, before he dropped serve and allowed his opponent to control proceedings and take the set 7-5 with his fourth ace of the day.

"Yeah, I expected a very tough match", Murray said after raising his record against the Argentine to 7-3.

Playing his first Roland Garros since 2012, Del Potro walked off Court Philippe Chatrier to a roaring standing ovation - one the notoriously tough French crowd wouldn't give to just anyone.

World No. 1 Murray triumphed 7-6 (10/8), 7-5, 6-0 for his seventh win in 10 meetings with Del Potro whose challenge fizzled out after squandering four set points in the 87-minute opener.

"It's slow and heavy and coming back in these conditions is hard".

Having started the tiebreak with a double fault Murray got better to reach 6-4. But mentally I feel pretty good just now.

Switzerland's third seed Stan Wawrinka progressed after claiming a 7-6, 6-0, 6-2 win over Italy's Fabio Fognini. The match, you suspect, hung on the outcome of a titanic first set that lasted almost 90 minutes. Next for Wawrinka: No. 15 Gael Monfils or No. 24 Richard Gasquet, a pair of Frenchmen whose match was suspended in the first set Saturday because of rain that washed out play in the evening.

Murray must wait to discover who he will face in the last 16 as John Isner and Karen Khachanov had only played a set when the rain arrived in Paris on Saturday and the Scot is not looking beyond the next round.

The Scot served for the set at 5-4 but the former US Open champion struck back with some piledriven forehands to knot matters at 5-5. That's very positive, because I wasn't doing that for the last few tournaments and the last couple of matches I have done it, and totally turned the matches around.

Both Frenchman are now 30 years old, and after setting a record of 30 over-30s in the second round of a Grand Slam, this Roland Garros was still boasting a remarkable 13 of them in the third round-more than half the remaining players. With some exquisite returning and acutely angled groundstrokes, Murray raced through the final set and into the fourth round.

Other men advancing before the downpour: 2014 U.S. Open champion Marin Cilic, Kevin Anderson and Fernando Verdasco.

In the women's competition, Alize Cornet of France reached the last 16 for just the second time with a 6-2, 6-1 win over Polish ninth seed Agnieszka Radwanska, who lost all her seven service games.