Rafael Nadal beats Leonardo Mayer to make Mexico semi-final

Rafael Nadal beat Argentina's Leonardo Mayer 6-1 7-5 to reach the Mexican Open semi-finals as he continues his comeback from a knee injury.

The Spaniard, 26, was playing his third tournament in four weeks since returning from a seven-month lay-off.

Nadal injury timeline

14 July 2012: Pulls out of an exhibition match with Novak Djokovic because of tendinitis

19 July: Withdraws from the Olympics with tendinitis in left knee

15 August: Withdraws from the US Open

3 September: Announces he has a partially torn patella tendon

25 December: Pulls out of the Abu Dhabi exhibition with a stomach virus

28 December: Withdraws from the Australian Open because of the virus

5 February 2013: Nadal returns alongside Juan Monaco in the Vina del Mar doubles before playing his first singles match 24 hours later

The 11-time Grand Slam champion was runner-up at the Chile Open before winning the Brazil Open two weeks ago.

"This was a very difficult match. Leonardo was playing really well in the second set," Nadal said.

"He began to play more aggressive and his serve was working well."

Nadal breezed through the opening set of the quarter-final but had to survive two break points in the third game of the second on his way to victory.

He next faces the toughest test of his comeback to date against compatriot and two-time Acapulco champion Nicolas Almagro, with top seed and world number four David Ferrer a potential final opponent.

Almagro, ranked 12th, beat Horacio Zeballos of Argentina 6-3 6-4, while Ferrer saw off Italy's Paolo Lorenzi 6-3 6-1 to book a semi-final clash with Fabio Fognini.

"I don't feel like the favourite for tomorrow," said Nadal. "It's been seven months without competing and I will be facing a great clay player.

"I will do my best to play a great match to reach the final, it's that clear."

Despite continuing to experience pain in his knee, Nadal remains scheduled to play the upcoming hard court Masters Series events at Indian Wells and Miami, but will make a final judgement on that after Acapulco.

"So far I've played in three semi-finals and that's fantastic news, and it's even better because my three best games have been here," he said.

"Now I feel like I have nothing to lose no matter what happens tomorrow. Either I will go on to play the final or I will go happy to play in another tournament knowing that the knee is responding better."