Garbine Muguruza made light work of Iga Swiatek to book her place in the quarter-finals of the Dubai Tennis Championships.

The in-form Spaniard required just one hour and nine minutes to win 6-0 6-4 against the number eight seed and reach the final eight for the fourth time in seven appearances at the tournament.

Reigning French Open champion Swiatek came into the contest on a six-match winning streak but her resistance seemed to falter after she dropped serve in the opening game and then failed to capitalise on two break points in the second.

Muguruza, whose 2021 record now stands at 15 wins and four defeats, was comparatively ruthless against an opponent who landed with just 38 per cent of her first serves.

The former world number one and double grand-slam champion let a 3-1 lead slip in the second set before resuming control through her punishing forehand, getting the job done on the first match point with an ace.

She will be back into action on Thursday against Aryna Sabalenka. The Belarusian, who beat Anett Kontaveit 6-3 6-2, lost in three sets to Muguruza at the Qatar Open last week.

"Back-to-back matches is good," said Muguruza. "That means I'm playing the top players, that means I'm getting into the deep rounds. I'm looking forward for another battle."

Coco Gauff reached the last eight of a WTA 1000 event for the first time after a straight-sets win over qualifier Tereza Martincova.

The American, who turns 17 on the day of the final, won 6-4 6-2 to set up a showdown with Jil Teichmann, a 6-3 6-3 winner over Ons Jabeur.

Second seed Karolina Pliskova was a surprise casualty, losing in less than an hour to Jessica Pegula. The world number 36, who also beat Pliskova in Qatar, will face Elise Mertens after she beat Caroline Garcia 6-4 6-2.

The last remaining former champion in the draw, Belinda Bencic, suffered disappointment on her 24th birthday as she lost 6-1 2-6 7-5 to wildcard Anastasia Potapova. She will take on Barbora Krejcikova, who eliminated Svetlana Kuznetsova.