World No. 1 Rafael Nadal brushed aside Portugal's João Sousa 6-1, 6-0 in just one hour and 15 minutes to advance to the semifinals of the inaugural Rio Open.

The 27-year-old Spaniard is playing his first tournament since injuring his back during this year's Australian Open final, which he lost to Switzerland's Stanislas Wawrinka, and says he is still not fully recovered.

But in Friday night's match at the Jockey Club Brasileiro, Nadal served with more authority - recording four aces - and played at a higher level of intensity than in his first two contests, giving his 48th-ranked opponent little chance to compete.

Sousa had three chances to break Nadal's serve midway through the first set, but he squandered the first one by not swinging at a deep ball that clipped the line. That mental error proved costly as the Spanish great rallied from 0-40 down to hold serve.

Nadal was also typically strong with his return game, creating 10 break points and converting five of them.

"I improved everything. I played a quite complete match," the Spaniard said in the post-match press conference.

"Not only the best (match) of the tournament. I played at a high level. I was able to do things I didn't do in other matches. I was more aggressive, more intense," the world No. 1 said.

Next up for Nadal in Saturday's second semifinal will be countryman Pablo Andujar, who trounced another Spaniard, Tommy Robredo, 6-1, 6-1 on Friday.

The first semifinal will pit second-seeded Spaniard David Ferrer, a 4-6, 6-3, 6-3 winner over Brazil's Thomaz Bellucci in Friday's only closely contested quarterfinal, against Ukraine's Alexandr Dolgopolov, who routed Italy's Fabio Fognini 6-1, 6-1. EFE