World number one Ashleigh Barty of Australia swept aside Latvia's Jeļena Ostapenko to set up a meeting with three-time champion Victoria Azarenka in the last 16 of the Miami Open.
Barty made light work of Ostapenko in a 6-3, 6-2 victory at Hard Rock Stadium.
The top seed will face Azarenka for a place in the quarter-finals after the Belarusian beat Germany's Angelique Kerber 7-5, 6-2 in a battle of two Grand Slam winners.
Two-time Wimbledon champion and ninth seed Petra Kvitová is also through after dispatching Britain's Johanna Konta 6-1, 6-2.
The reward for the Czech player is an encounter with Ukraine's fifth seed Elina Svitolina, who defeated Russia's Ekaterina Alexandrova 7-6, 6-4.
In the men's draw, second seed Stefanos Tsitsipas of Greece ousted Bosnia and Herzegovina's Damir Džumhur to reach the last 32.
Tsitsipas, a semi-finalist at last month's Australian Open, won 6-1, 6-4 and will next play 28th seed Kei Nishikori of Japan.
Nishikori needed three sets to get past Slovenia's Aljaž Bedene 7-6, 5-7, 6-4.
Fourth seed Andrey Rublev of Russia had no such issues as he thrashed Tennys Sandgren 6-1, 6-2 to book a clash with Márton Fucsovics of Hungary.
The Women's Tennis Association 1000 and Association of Tennis Professionals Masters 1000 tournament continues tomorrow.