South Africa's Gershon Rorich and Colin Pocock have created history at the Olympic beach volleyball event.
The pair became the first team from Africa to reach the last 16 following a 22-20 22-20 win over Portugal's Migule Maia and Joao Brenha.
Switzerland's Patrick Heuscher and Stefan Kobel will join the them after a 21-16 13-21 15-13 win over Americans Dain Blanton and Jeff Nygaard.
Blanton and Nygaard finished bottom of their pool with a 0-3 record.
In the women's competition, Sydney gold medallist Kerri Pottharst of Australia and her new partner, Summer Lochowicz, saw off the challenge of Mexico's Hilda Gaxiola and Mayra Garcia with a 26-24 22-20 victory.
A roaring crowd helped inspire Greece pair Effrosyni Sfyri and Vasiliki Karadassiouto beat China 21-14 21-17.
Each team plays three preliminary round matches.
The two top teams and four best third-place teams move on to the single-elimination round of 16 which begins on Friday.