Rafa Nadal battled to a 6-3, 6-7, 6-1 win over Argentine Martin Alund in Sao Paulo on Saturday to qualify for the Brazil Open final.
The former world number one Nadal will meet David Nalbandian in Sunday's final, the Argentine veteran having defeated Italian Simone Bolelli 6-3 7-5 in the other semi-final.
Nadal, who is playing just his second tournament in seven months after a long lay-off with a serious knee injury, was pleased to have reached the final just a week after doing the same in his comeback tournament in Chile.
The Spaniard warned he was still a long way from his best, however, and rated Nalbandian favourite to win the trophy.
"After being out for seven months, if the knee isn't good and I can reach two finals, that can only be positive," he said.
"Physically, I am prepared. I don't know (whether) the knee is prepared," he added with a smile.
Nadal was a shock loser to Argentine Horacio Zeballos in three sets in the final of the Chilean Open.
The 11-times Grand Slam champion is expected to play another clay court tournament in Acapulco this month as he gears up to defend his French Open title in May.