VINA DEL MAR, Chile — Rafael Nadal lost the singles and doubles finals at the VTR Open on Sunday in a disappointing finish to his comeback tournament after being sidelined for seven months with a left knee injury.

Nadal was beaten by Argentina’s Horacio Zeballos in three sets in the singles final. Then Nadal and partner Juan Monaco lost 6-2, 6-4 in the doubles championship against the Italian pair of Paolo Lorenzi and Potito Starace.

Nadal was an overwhelming favorite, particularly in singles where he was shooting for this 37th singles title on clay. But Zeballos won 6-7 (2), 7-6 (6), 6-4 for his first title on any surface, looking every bit the equal of the seven-time French Open champion.

It was only the fifth loss for Nadal in a singles final on clay.