Nadal, Serena ease into last 16 in Madrid
Spanish player Rafael Nadal returns the ball to Argentinian player Juan Monaco during their men's singles second round tennis match of the Madrid Masters at the Magic Box (Caja Magica) sports complex in Madrid on May 7, 2014 - by Pierre-Philippe Marcou
Monaco failed to win a game on serve all match as Nadal, who suffered shock defeats in Monte Carlo and Barcelona, rolled off 10 straight games to seal victory in little over an hour.
He now meets Finland's Jarkko Nieminen.
"Obviously once you lose a match it takes a bit longer to find the confidence in your movement and your shots," admitted the 13-time Grand Slam champion.
"Once it went to 4-1 in the first set I felt I played a lot better and I am happy with the way I felt on court today."
Nadal is the only top four seed remaining in the men's draw as Novak Djokovic and Roger Federer withdrew due to injury and family reasons respectively, while Stanislas Wawrinka lost to Austrian qualifier Dominic Thiem on Tuesday.
However, the Spaniard insists he has not been distracted by the draw appearing to open up perfectly for a fourth title in Madrid.
"In the past two tournaments I didn't get to the rounds where I would have played those players anyway.
"At this level all the opponents are difficult and next I will face Jarkko who has huge experience form being on the tour so many years.
"I congratulate Roger on becoming a father again and wish Novak the best in his recovery."
Serena Williams also cruised into the last 16 of the WTA Madrid Open with a 6-2, 6-3 thrashing of China's Peng Shuai.
The 17-time Grand Slam champion powered through the first set against the world number 42 for the loss of just one point on her own serve.
Peng showed more resistence in the second, but couldn't convert on two break points and Williams needed just one chance to seal the only break of the set, before serving out the match to set up a third round meeting with Spain's Carla Suarez Navarro.
Williams wore heavy strapping on her left leg throughout the match, but insisted there is no serious injury to worry about.
"It's okay. I was just taping it to make sure it stays kind of warm and ready. I just had some issues and went preventive to make sure I didn't make anything worse," she said.
"I'm literally taking it one day, one match at a time, and not putting any pressure on myself here."
Fourth seed Simona Halep also had a comfortable passage into round three as she saw off Spain's Lara Arruabarrena 6-4, 6-4.
However, there was disappointment for 13th seed Caroline Wozniacki as she was beaten in straight sets 6-3, 6-3 by Italian Roberta Vinci.
Elsewhere, world number six Thomas Berdych stretched his perfect record against South African Kevin Anderson to 11-0 with a 6-1, 6-4 win.
"I always like to play here. The courts are great, very well prepared. It's a bit faster because of the altitude, which suits my game well and means I can serve well and play aggressively," said the Czech number one.
"I think we have similar games, but I can always find something extra and that's the difference. It's also probably a mental thing as well now.”
Ninth seed John Isner of the United States sealed victory with the only break of serve in the match to overcome Australia's Marinko Matosevic 7-6 (11/9), 6-7 (5/7), 7-5.
Polish lucky loser Lukasz Kubot made the most of Federer's withdrawal by beating Frenchman Gilles Simon 7-5, 2-6, 6-4 and Latvia's Ernests Gulbis also advanced with a 6-3, 6-4 win over Ukrainian Alexandr Dolgopolov.