Rafael Nadal’s grip on the French Open title was in danger of being loosened by the unlikely figure of Diego Schwartzman.

The man who has lost just twice in 85 matches at Roland Garros was staring down the barrel of a shock defeat when the rain saved him.

At one point Nadal, the reigning champion and 10 times winner, found himself a set and a break down to the diminutive Argentinian Schwartzman.

It was the first set Nadal had lost in his last 38, stretching over three French Open campaigns – meaning Bjorn Borg’s record of 41 straight sets won remained intact.

However, when the players came back on after a delay of almost an hour Nadal immediately broke back to level the second set.

A hold and a break later he was serving to level the match, but at 5-3 and 30-15 the heavens opened again and they were forced off once more, this time for good.

He may have halted the mutiny for now but Nadal was strangely off-colour, unable to dictate the rallies as he usually does on clay.

Schwartzman, the 11th seed, was certainly playing out of his skin, but even that should have not been enough to trouble a Nadal playing anywhere near his peak.

Nadal’s serve, and forehand, had seemingly deserted him as he was broken three times in the first set. He hit straight back on two occasions but Schwartzman held to take it 6-3.

Three consecutive breaks – two for Schwartzman – gave the 25-year-old underdog the advantage in the second set before the first rain break. Nadal had faced 12 break points, losing five of them.

The enforced interlude had clearly benefited Nadal, and assuming he gets the two points he needs to level the match he will start a strong favourite on Thursday.

In the second quarter-final Marin Cilic and Juan Martin Del Potro were locked together at 5-5 in a first-set tiebreak before rain suspended play.

-AAP