They started the three-star Beach World Tour event with a 21-18, 21-12 Pool G win over France's Romain Di Giantommaso and Jeremy Silvestre.

This was backed up by a 21-13, 21-16 success over Americans William Kolinske and Miles Evans.

"We are very happy to finish top of the pool," Marco Grimalt said. 

"Our service was very good and side-out too. 

"We played good block-defence, so in general, we played well."

Elsewhere, Qatar's Ahmed Tijan and Cherif Younousse took control of Pool A with two wins of their own.

They beat home Japanese players Yu Koshikawa and Hiroki Dylan Kurokawa 21-7, 21-6 and then saw off Americans Chase Budinger and Sean Rosenthal 21-18, 24-22.

Success for the United States came through Casey Patterson and Stafford Slick who lead Pool D after beating Japan's Yoshiumi Hasegawa and Keisuke Shimizu 21-17, 21-18 and Norway's Mathias Bertnsen and Hendrik Nikolai Mol 17-21, 22-20, 15-10.

In the women's event, home joy came through Japan's Miki Ishii and Megumi Murakami who won their clash in straight sets against Americans McKenna Thibodeau and Madison Witt, 21-14, 21-14.