Latvian Jelena Ostapenko showed more glimpses of the form that fuelled her 2017 title triumph at Roland Garros in a 6-4 6-2 second-round demolition of second seed Karolina Pliskova.
Pliskova's twin Kristyna joined her sister in going out of the tournament after losing to former champion Garbine Muguruza, who sealed a routine 6-3 6-2 victory.
Australian Open champion Sofia Kenin was made to work hard by Romanian Ana Bogdan before sealing a 3-6 6-3 6-2 win while fellow American and 2018 runner-up Sloane Stephens lost 6-4 4-6 6-2 to Paula Badosa of Spain.
Ostapenko said: "It's hard to compare because that was three years ago and I was fearless, nobody really knew me, but now players get to know me more. They know how I can play. They know how to play probably against me.
"Of course it's in my memory because it's the biggest win of my career so far, but I have to move forward and the world doesn't stop with winning only one grand slam.
"Of course I want to achieve more and I want to be back in the top five, top 10. Step by step. That's what I'm working on, my consistency. Still being an aggressive player, I think it can bring me a lot of wins, but consistency probably in my game is the key."
Ostapenko produced plenty of winners against Pliskova - 27 in total - but she was also content to stay in rallies, pulling her opponent around the baseline and throwing in several successful drop shots.
"I think I was playing good today," said Ostapenko. "I knew it was going to be a tough match, so I was trying to be very focused all match. Just playing my game.
"Also just trying to keep the ball in play to make sure I'm not missing and making too many unforced errors. But when I had the chance I was going for it."
Pliskova (above) has been a permanent fixture in the top 10 for the past five years but has underperformed at the slams, going beyond the fourth round just once in the last two seasons.
The Czech said: "I'm sure I could do much better. I know that she can be tough if she's playing well, but I think everything started with me."
Seventh seed Petra Kvitova was more convincing in a 6-3 6-3 victory over Jasmine Paolini, and eighth seed Aryna Sabalenka defeated Daria Kasatkina 7-6 (6) 6-0.
It was the end of the road, though, for 17-year-old qualifier Clara Tauson, who upset Jennifer Brady in round one but was beaten 6-2 6-3 by Danielle Collins in the second round.
