Monte Carlo : Rafael Nadal overcame a second set slip-up as he reached the quarter-finals of the Monte Carlo Masters with a battling victory over John Isner .

The Spaniard was extended into a third set by Isner, but quickly regained command to seal a 7-6 4-6 6-3 win in the third round.

Making his return to the clay courts, Nadal had eased past Lucas Pouille in his opening clash, and received a more testing workout against the American powerhouse.

In a tense opener, Nadal was forced to save two set points before he edged out Isner in the tie-break. 

But the Florida man mounted a determined response in the second set, breaking the eight-time winner to level the match.

Any doubts about Nadal's fragile fitness were answered in the third as he broke Isner's booming serve again and powered to victory with his trademark ground strokes to the fore. He will next face David Ferrer - who saw off home hope Gilles Simon in three sets, coming through 6-2 6-7 6-1 - for a place in the semi-finals.

Nadal said: "I lost in three sets in Rio. I lost in three sets in Indian Wells. I lost in three sets in Miami, so to break this streak of three-set losses was important."

Meanwhile, Novak Djokovic, the 2013 Monte Carlo winner and a two-time runner-up, needed lees than a hour to see off Austria's Andreas Haider-Maurer 6-4, 6-0. 

Next up for the No 1 seed will be Marin Cilic, the eighth-seeded Croat beating Frenchman Jo-Wilfried Tsonga 6-3 7-6; Cilic has never beaten Djokovic in 11 meetings.

Courtesy SkySport