Sorana Cirstea progresses at Miami Open

Puig broke Cirstea as she served for the match but the Romanian did not make the same mistake twice and served out for victory.

"I'm very happy to finish in two sets. I think I started strong; towards the end of the second set I kind of backed off," Cirstea told reporters after the match, "I'm happy with how I fought and the way I won the last game."

Australian Ashleigh Barty, who won the Malaysian Open earlier this month, continued her fine form with a 6-4 5-7 6-3 victory over Eugenie Bouchard.

Jelena Jankovic suffered a 4-6 6-4 7-6 (7/3) defeat to Yaroslava Shvedova, while Lucie Safarova beat Yanina Wickmayer 7-6 (7/2) 6-4.

Patricia Mariatig got the better of Britain's Heather Watson 7-6 (7/4) 6-1, and American qualifiers Taylor Townsend, Varvara Lepchenko and Madison Brengle all advanced.

Home hopes Bethanie Mattek-Sands, Christina McHale and Shelby Rogers also made progress, while there were also victories for Julie Goerges, Risa Ozaki, Anett Kontaveit, Aliaksandra Sasnovich, Pauline Parmentier, Ajla Tomljanovic, Qiang Wang, Veronica Cepede Royg and Jana Cepelova.