(Recasts with Murray win)
MADRID May 7 (Reuters) - Andy Murray showed plenty of mental strength to come through 6-1 1-6 6-4 against Nicolas Almagro on Wednesday to keep on track his bid to win the Madrid Open.
The seventh-seeded Scot returned to singles action having taken a break in an inconsistent year that has seen him fall down the rankings.
Earlier, Rafa Nadal launched the defence of his Madrid Open title by breezing past Juan Monaco 6-1 6-0 to rediscover his touch on his favoured clay after surprise exits in his last two tournaments.
The world No 1 went out in the quarter-finals at both Monte Carlo and Barcelona last month, but his extra quality shone through in his second-round match against the 56th-ranked Monaco.
Murray made a storming start against Almagro, with two breaks of serve on his way to winning the first set.
He outplayed the Spaniard with his power and speed around the court but the second set was very different, as Almagro found his range and Murray's head went down.
Almagro, who knocked Nadal out of the Barcelona Open, looked in charge but it was a much tighter final set, in which Murray rediscovered his consistency to win.
"It was a tough match, he was going for bombs with every shot and huge serves. He was ripping the ball from the back of the court," Murray told reporters.
Admitting that he does not find it easy on clay, he added: "I have been struggling on it in the last few years, physically. It's a question of keeping on top of the recovery. The aim is to stay fit for the French Open and the next few weeks are very important."
Nadal, seeking a fourth Madrid Open title, established a 2-0 lead and never looked back.
Although he was not at his best, the power and accuracy of his shots were too much for the Argentine, with the match ending in 68 minutes.
The Spaniard is gearing up for the French Open at Roland Garros, where he has won a record eight titles.
In the last nine seasons, he has won at least two European claycourt titles ahead of the French grand slam, but he is yet to win in his home continent this year, with his only 2014 victory on the red dust coming in Rio de Janeiro in February.
"All the wins are useful to improve your confidence. At the start it was more difficult, I moved nervously. Then after that I played better than I have been doing," Nadal told reporters.
He now faces a quarter-final against Jarkko Nieminen, who beat Igor Sijsling 6-3 6-2.
"We know each other very well, we've played a lot of times. He is a fighter and left-handed as well so it will be a tough game," Nadal said of the 57th-ranked Finn.
Women's No 1 Serena Williams remained on track for her 60th career title as she powered past Peng Shuai 6-2 6-3 in Madrid.
It has been a patchy season for the American, who won the Miami Masters in March, but followed that by exiting in the early rounds in Charleston.
Having taken a month out to rediscover her form she looked strong against Peng, ranked 42 in the world, winning eight of the first nine points to break serve.
Williams was dominant on her serve and the Chinese failed to unsettle her. Williams now faces a quarter-final against Spanish No 1 Carla Suarez Navarro, who beat Alison Riske 6-2 6-4.
(Writing by Tim Hanlon in London; Editing by Toby Davis and Stephen Wood)