The second-seeded Nadal needed just 85 minutes to beat Alund at the
clay court tournament and will next face another Argentine in Leonardo
Mayer, who defeated Russia's Andrey Kuznetsov 6-2, 6-2 to advance.
Top Seeded David Ferrer earlier downed American Wayne Odesnik 6-2, 6-1 to book his place in the final eight.
Nadal is making a comeback after being away from the tour for more than seven months with a left-knee injury.
He made the final of the VTR Open earlier this month in Chile before losing to Argentine Horacio Zeballos.
A week later he beat David Nalbandian to claim the Brazil Open title
Top Seeded David Ferrer earlier downed American Wayne Odesnik 6-2, 6-1 to book his place in the final eight.
Nadal is making a comeback after being away from the tour for more than seven months with a left-knee injury.
He made the final of the VTR Open earlier this month in Chile before losing to Argentine Horacio Zeballos.
A week later he beat David Nalbandian to claim the Brazil Open title
