Irrepressible, indefatigable, incredible.

Rafael Nadal completed the dream comeback to hard courts last night as he wore down Juan Martin Del Potro 4-6, 6-3, 6-4 to win the BNP Paribas Open.

As he fell to the court, it was as if he had won another grand slam title. Since returning to the Tour in February after seven months out through injury, Nadal has now won three of his four tournaments. As we head towards the European clay-court season, his rivals must be quaking in their boots.

"There were some very tough moments in the seven months," Nadal said. "My movements today were unbelievable – I ran for some balls that three weeks ago I did not know if I would be able to do again.

"My comeback is going amazing. I am very happy with the way I am playing and it gives me a lot of confidence to win a tournament like this."

For a set and a half it looked as if reality might, finally have set in. Having beaten an ailing Roger Federer and then Czech Tomas Berdych to reach the final of his first hard-court event in a year, he found himself a set and 3-1 down to a Del Potro playing fantastic tennis. But he simply refused to give in and at 2-0 down, he gave himself a "vamos" of encouragement. All it took was for Del Potro, who had been cranking winners on his huge forehand, to drop his level a little and the Spaniard roared his way back to level at one set apiece.

Del Potro, who had beaten Andy Murray in the quarter-finals and then world No.1 Novak Djokovic in the semis, saved three break points at the start of the decider but Nadal thumped a forehand to break two games later.

The Spaniard held serve easily throughout the rest of the set and then, after missing three match points on the Del Potro serve, served out for victory, falling on to his back and then embracing his team in utter delight.

Nadal will skip this week's Miami tournament to allow his knee to rest but will return to action in Monte Carlo next month, a tournament he has won eight times in a row.

The women's title was won by Russia's Maria Sharapova, who hammered Caroline Wozniacki 6-2, 6-2 to win her 20th career title but her first since she lifted the French Open trophy last June.

Sharapova, who rises to world No.2, has now won at least one title every year for the past 11 years and her win was more evidence that she is playing as well now as at any time since she returned after career-threatening shoulder surgery in 2009.

"We're very fortunate to play this sport but what makes it extra special is when you come out a champion," Sharapova said. "It's never nice when you lose but moments like this make it very special. I'm much calmer about my career after my injury and I am healthy, that's the key."

Andy Murray, meanwhile, is confident he will be back on top form in his "home" Masters 1000 event in Miami this week, thanks to Ivan Lendl's return to courtside.

Lendl was not in Indian Wells to see Murray reach the quarter-finals but fall short to an inspired Del Potro. The pair's relationship has been an undoubted success story, bringing with it an Olympics triumph and a first grand slam title at the US Open.

"Having him around helps everyone in the team, because of his experience, his understanding of the game and these sort of situations," Murray said.

The Scot struggled to cope with the conditions in Indian Wells and much prefers the heavier, humid arena in Miami, where he owns an apartment and where he trains for part of the year, including last month.

"I hope by Miami I should be playing much better," he said. "I know the conditions well there, I practice there regularly. I feel like when I play on those courts I can open up a bit more, play aggressively and time the ball better, so I would hope that if I can get through a round or two in Miami I'll start to play better and better."

Murray reached the final in Miami last year but can close the gap on Federer in the world No.2 spot with another good performance over the next fortnight.