Top seed Rafael Nadal overcame a second straight three-set outing to book a place in the Brasil Open final against short-lived doubles partner David Nalbandian.

Nadal needed nearly two hours to beat unheralded Argentinian Martin Alund 6-3 6-7 (2/7) 6-1, just 24 hours after beating Carlos Berlocq in three sets in the quarter-finals.

After booking his place in a second straight final following a long spell out with injury, Nadal admitted he had felt some discomfort in his troublesome left knee.

"It was the worst day for my knee, and if the knee is not well it makes it very difficult to play," he said.

"But I am happy with the result. After seven months without playing it's good to reach the final again, even if I'm not at my best."

Nadal has certainly hit the comeback trail all guns blazing, reaching finals in Chile and Brazil, where he also entered the doubles draw alongside Nalbandian.

That partnership proved shot lived as Nadal withdrew after one match to protect his knee, but the pair will reunite in the singles final after Simone Bolelli of Italy 6-3 7-5.