American Pegula, who is currently enjoying her highest career singles ranking, demolished Pliskova of the Czech Republic, triumphing 6-0 6-2 in under an hour on third round day at the Dubai Duty Free Tennis Stadium.

With top seed Elina Svitolina of Ukraine a casualty in round two yesterday, that left Aryna Sabalenka of Belarus as the highest seed in the tournament.

Sabalenka enjoyed a smooth passage to the last eight with the third seed beating Anett Kontaveit of Estonia, the 15^th seed, 6-3 6-2.

Wildcard Anastasia Potapova of Russia also caused an upset on day four of the tournament in the United Arab Emirates, as she defeated sixth seed Belinda Bencic of Switzerland 6-1 2-6 7-5.

Elsewhere, ninth seed Garbine Muguruza of Spain comfortably beat eighth seed Iga Swiatek of Poland 6-0 6-4 in a clash of two French Open champions, while tenth seed Elise Mertens of Belgium was also a straight sets winner, overcoming Caroline Garcia of France 6-4 6-2.

The doubles draw in Dubai has reached the second round stage, and as well as being responsible for the biggest upset on the singles side today, Pegula also helped cause the biggest shock in the doubles.

Playing alongside fellow American Bethanie Mattek-Sands, the qualifiers defeated top seeds Mertens and Sabalenka, both winners in the singles today, 3-6 7-6 10-6.