The American duo beat Canada's Grant O'Gorman and Michael Pantinga 21-11, 22-20 as pool stage began at the Beach World Tour event.

It means they are guaranteed a spot in the elimination bracket at the very least.

All of the men's pairs played one pool game today and face two more tomorrow.

Hyden, the oldest player competing, and Doherty, a former professional baseball player, are seeking to reach an international quarter-final for the fourth time this term.

In 2014, Hyden became the oldest player to win a World Tour event as he partnered Tri Bourne to victory in Berlin.

They beat Doherty and Nick Lucena in an all-American final.

There was also a victory today for Brazilian Olympic champions Bruno Oscar Schmidt and Alison Cerutti, who defeated Germans Markus Böckermann and Lars Flüggen 21-14, 21-14.

Another Brazilian duo, George Souto Maior Wanderley and Vitor Felipe, lost out to home hopefuls Bartosz Losiak and Piotr Kantor, 21-15, 23-25, 15-13.

In the women's tournament, each pairing played two group matches each.

The biggest shock saw Kristyna Kolocova and Michala Kvapilova of the Czech Republic beat Brazil's Agatha Bednarczuk and Eduarda Lisboa, the second-ranked team on the World Tour.

The Czechs won 22-20, 21-16.

They had earlier beaten Elsa Baquerizo and Amaranta Navarro of Spain, 22-20, 21-16.

Top-seeded Talita Antunes and Larissa Franca of Brazil also won both of their matches to win their group.

The World Tour event is taking place a week before the FIVB World Beach Championships in Austria.

Competition in Vienna is due to be held from July 28 until August 6.