Rafael Nadal continued his comeback from a back injury by crushing fellow Spaniard Albert Montanes 6-1 6-2 to reach the last eight of the Rio Open.

The top seed, playing in his first tournament since losing to Stanislas Wawrinka in the Australian Open final, broke three times in each set, dropping his serve once in the second, as he made short work of his compatriot.

Nadal will now face Portuguese world number 48 Joao Sousa after he overcame Spain's Albert Ramos 7-6 (8/6) 2-6 6-3.

Fabio Fognini, the third seed from Italy, survived a second-set scare as he recorded a 7-6 (7/1) 4-6 6-3 win over Argentinian Pablo Cuevas.

Next up for Fognini is Ukraine's Alexandr Dolgopolov, who came from a set down to defeat Uruguayan qualifier Facundo Bagnis 6-7 (4/7), 6-2, 7-6 (7/4).

In the women's draw fifth seed Kurumi Nara from Japan swept past Germany's Anna-Lena Friedsam 6-0 7-6 (7/3).

Spain's Lourdes Dominguez Lino came from a set down to knock out South Africa's Chanelle Scheepers 2-6 7-6 (9/7) 6-1.

Brazil's Teliana Pereira and Romanian qualifier Irina-Camelia Begu were other second-round winners.