Rafael Nadal battled into the fourth round of the Madrid Open with a hard-fought win over Argentina's Pedro Cachin.

The 37-year-old is still playing within himself as he bids to build his fitness for the French Open next month.

He cruised through the first set but lost a scrappy second in a tie-break before eventually sealing a 6-1 6-7 (5) 6-3 victory in a little more than three hours.

Five-time winner Nadal, playing at his home tournament for probably the last time, said on Sky Sports: "I found a way to be through. In the third I was able to be more unpredictable and I think that changed the match.

"I'm enjoying the fact that I'm playing at home because it means everything to me and I'm trying my best to keep dreaming - and tomorrow is another day."

Play was briefly halted in the first set while a spectator required medical treatment, with Cachin rushing to the players' fridge to send bottles of water into the stand.

When they resumed Nadal promptly secured a third break of serve to wrap up the set.

But Cachin began swinging at the start of the second and broke the Nadal serve twice to lead 4-1 and silence the sell-out Spanish crowd.

The 22-time grand slam champion upped the intensity and retrieved one break before saving two set points in a marathon 10th game to level the set at 5-5.

Cachin looked on the verge of forcing a decider with another break but once again he wilted and Nadal hit back, the old warrior spirit coming to the fore as he celebrated taking the set to a tie-break with four fist pumps.

But an audible groan went up from the crowd when Cachin brought up a set-point on the Nadal serve and passed the veteran to level the match.

However, Nadal secured a break at the start of the third and had to dig deep to ward off the threat of Cachin, who looked to assert himself in the decider.

Ultimately, Nadal's quality shone through as he claimed victory to set up a fourth-round meeting with 22-year-old Czech Jiri Lehecka.