World number two Iga Swiatek showed why she is next in line to occupy the top ranking as she comfortably handled the challenge of 14 seed Cori Gauff 6-3 6-1 to earn a spot in the quarter-finals at the Miami Open.
Swiatek, 20, will become the first Polish-born man or woman to earn the number one singles ranking when it is next updated on April 4, after Ash Barty's retirement, and she never gave Gauff a chance.
She won all eight of her service games in the match, and broke Gauff's serve four times in eight chances to rattle off five consecutive games to close the match.
After a walkover in her last fixture, Naomi Osaka was strong on her way to a 6-3 6-4 win against Alison Riske.
Both women produced break points throughout the match, but while Osaka saved seven out of eight, coming back to double-break after her slip-up in the second set, Riske could only save nine of 12.
In a clash between top-10 seeds, Danielle Collins was terrific in her 6-2 6-4 win against Ons Jabeur.
The match was decided by each woman's success on their second serve, as Jabeur had the better first serve, but could only win 31 per cent of her second serves (8-26), while Collins was an even 73 per cent on both her first and second attempts.
Daria Saville continued her march back up the rankings with a 5-7 6-4 7-5 win against Lucia Bronzetti, making it nine wins from her past 10 matches for the Australian ranked 249 in the world after recently returning from a long-term achilles injury.
Saville will play Switzerland's Belinda Bencic after she breezed past Belarus' Aliaksandra Sasnovich 6-2 6-3, while Petra Kvitova got the better of higher-ranked Veronika Kudermetova 7-6 (7-5) 6-4.
American Jessica Pegula was nearly flawless on her way to a 6-0 first set before Ukrainian Anhelina Kalinina retired due to injury, while world number six Paula Badosa beat wildcard Linda Fruhvirtova 6-2 6-3.