Jelena Ostapenko continued her excellent form by brushing aside second seed Barbora Krejcikova to reach the Qatar Open quarter-finals on Wednesday, while top seed Aryna Sabalenka eased through.
Former French Open champion Ostapenko, who won the title in Dubai last week, cruised to a 6-3, 6-2 victory to set up a last-eight tie with either Garbine Muguruza or Madison Brengle.
Ostapenko, who dropped out of the world's top 50 last year, has won eight straight matches, including five against Grand Slam winners.
The 24-year-old is closing in on a return to the top 10, having climbed to 13th in the rankings ahead of this week.
She was far too strong for world number three and reigning Roland Garros champion Krejcikova, breaking the Czech's serve five times.
Ostapenko is bidding to win a WTA 1,000 tournament for the first time in her career.
Third seed Paula Badosa was also knocked out in the last 16, losing 6-2, 6-3 to Coco Gauff.
It was the fifth time the 17-year-old Gauff has beaten a top-10 player, but the first since last May.
The American will take on Maria Sakkari for a semi-final spot, after the Greek's 6-4, 7-5 win over Jessica Pegula.
Belarusian world number two Sabalenka swept past Swiss player Jil Teichmann 6-2, 6-1 in just 65 minutes.
The 2020 Doha champion won 10 of the last 11 games in a dominant performance as she seeks to win her first title since last year's Madrid Open in May.
Tunisia's Ons Jabeur is also through after beating Tereza Martincova 6-1, 3-6, 6-3.
The eighth seed will play fourth-seeded Estonian Anett Kontaveit in the quarters after her 6-3, 0-6, 6-2 success against Elise Mertens.