China's Zhang Shuai and Elise Mertens of Belgium cruised into the women's doubles quarterfinals at the Miami Open on Sunday with a 6-3, 6-1 victory over Luisa Stefani of Brazil and Hungary's Timea Babos.

Seventh seeded pair Zhang and Mertens won 76% of their points on first serve and converted five of nine break points.

Stefani and Babos saved four of nine break points but managed to win just 52% of their first-service points.

Zhang and Mertens will meet Japan's Miyu Kato and Spanish Cristina Bucsa on Thursday for a place in the semifinals.

Kato and Bucsa advanced by beating Italian pair Jasmine Paolini and Sara Errani 7-6(4), 6-2 earlier on Sunday.