Spain's Rafael Nadal rallied for a 3-6, 6-4, 6-4 victory here over Argentina's Carlos Berlocq to advance to the semifinals of the Brazil Open.

Competing in his second straight small clay-court tournament after a seven-month hiatus from the ATP Tour due to injury and illness, the 26-year-old world No. 5 started poorly in Friday evening's quarterfinal match at Sao Paulo's Ibirapuera arena and was clearly outplayed in losing the first set.

Nadal played more aggressively in the second set and got his opponent scrambling from side-to-side on the baseline, eventually breaking serve in the 10th and final game to even the match.

That momentum swing did not last long, however, as Berlocq secured the first break of serve in the third set and had the victory in his sights.

But Nadal broke back to even the score at 3-3 and then clinched the match when Berlocq beat himself with two ground stroke unforced errors and a pair of double faults in the final game.

When a Berlocq forehand went wide on match point, Nadal showed how important the victory was to him by raising in arms to the sky and punching the air with his fist.

"I'm very happy to be in the semifinals. We'll see how I do from here on out," Nadal said when asked what he thinks of his title chances at the Brazil Open, a tournament he won as a teenager in 2005 when it was played in Costa do Sauipe.

Next up for Nadal will be Argentine lucky loser Martin Alund, who defeated Italy's Filippo Volandri 7-5, 7-6 (7-5).

The 111th-ranked Alund, who is in his first ATP Tour semifinal, acknowledged that Saturday's match against the 11-time Grand Slam champion and former world No. 1 will be the biggest of his career.

"I don't know (Alund) very well, but I know he's playing at a high level because he's already beaten tough opponents like Volandri and (French world No. 25 Jeremy) Chardy," Nadal said.

Nadal went off the ATP Tour due to a knee injury after suffering a shock second-round exit at last year's Wimbledon at the hands of unheralded Czech Lukas Rosol, considered one of the biggest upsets in the history of that prestigious tournament.

He had planned to return to action in late December in Abu Dhabi, but a stomach virus forced him to withdraw from that exhibition tournament and he also pulled out of the recently concluded Australian Open.

The Brazil Open is the second of three Latin American clay-court events Nadal signed up to play in February.

The Spanish star was upset in the final of Viña del Mar - his first tournament back - by Argentina's Horacio Zeballos. He also is scheduled to participate in the Mexican Open later this month.

Known for his physically demanding style of play and outstanding defensive skills, the Spaniard has struggled to stay healthy during his career and has been forced to withdraw from each of the four Grand Slam events due to various injuries.

The other Brazil Open semifinal will pit Argentina's David Nalbandian, who on Friday defeated defending champion and No. 2 seed Nicolas Almagro of Spain 7-6 (7-5), 3-6, 7-6 (7-3), against Italy's Simone Bolelli.

Like Nadal, the 31-year-old Nalbandian also is mounting a comeback after a months-long absence from the Tour.

Nadal and Nalbandian entered the Brazil Open doubles draw but they withdrew after winning their opening match because the Spaniard wanted to avoid overtaxing his knee. EFE