No.2 seeds Storm Hunter and Elise Mertens started their GNP Seguros WTA Finals Cancun campaign with a 6-4, 6-2 win over No.3 seeds Shuko Aoyama and Ena Shibahara in group play.

Hunter and Mertens, who won WTA 1000 titles in Rome and Guadalajara this season, took 1 hour and 16 minutes to win their first round-robin match of the week.

WTA Finals: Scores | Draws | Order of play

With the victory, Hunter and Mertens start round-robin play 1-0 in the Maya Ka'an Group. Aoyama and Shibahara, who picked up an opening win on Monday, are 1-1 in group play thus far.

Aoyama and Shibahara, both of Japan, started the match ahead, breaking for a 3-1 lead in the opening set. However, a winning volley by Australian Hunter put her team back on serve in the next game.

Later in the set, Hunter and Mertens broke the all-Japanese pair at love to lead 5-4. Belgian Mertens then served out the set at love as the No.2 seeds swept the last nine points of the set.

Hunter and Mertens eased through the second set without losing their serves. They finished the match with a 68 percent success rate returning the Aoyama/Shibahara second serves.

Mertens has now won her last six doubles matches at the WTA Finals. Last year, she and Veronika Kudermetova went an undefeated 5-0 en route to the title. She also was runner-up at the 2021 WTA Finals alongside Hsieh Su-wei.