Gauff, aiming to win her maiden Miami title, won 84 per cent of her first-serve points, saved the one break point she faced and converted six of her nine break points in the 47-minute match.
"I was definitely playing well today, and maybe she wasn't playing her peak great tennis," Gauff told reporters.
"I don't think anyone who is playing their best tennis will have that scoreline today, so I'm not going to sit here and say she played her best tennis."
Up next for Gauff, who was eliminated in the round of 16 at Indian Wells last week, will be Ashlyn Krueger who stunned seventh seed Elena Rybakina 6-4 2-6 6-4 for the first top-10 win of her career.
Top seed and two-times grand slam champion Aryna Sabalenka, playing her first match since losing to Mirra Andreeva in the Indian Wells final, broke Bulgarian Viktoriya Tomova six times en route to a 6-3 6-0 win.
Sabalenka will face qualifier Elena-Gabriela Ruse in the third round after the Bulgarian advanced with a 6-4 6-4 victory over Polish 29th seed Magdalena Frech.
Italy's Jasmine Paolini and Olympic champion Zheng Qinwen also advanced, and Canada's Leylah Fernandez beat American Alycia Parks 7-6 (7-1) 6-3.
Naomi Osaka upset No.24 seed Liudmila Samsonova 6-2 6-4, Ons Jabeur beat Katerina Siniakova 6-4 7-6 (9-7) and Linda Fruhvirtova thrashed No.16 seed Beatriz Haddad Maia 6-0 6-2.Â
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