Garbiñe Muguruza progressed to the Qatar Open round of 16 with a win over Romania's Sorana Cîrstea ©Getty Images

Both of last year's Qatar Open finalists, Spaniard Garbiñe Muguruza and Petra Kvitová of the Czech Republic, progressed to the next round in straight-sets victories.

Fifth seed Muguruza, the 2021 runner-up, survived a challenging first set against Romania's Sorana Cîrstea before cruising to a 7-6, 6-1 win.

"I feel like I started slow, and she was playing very aggressively since the beginning," Muguruza said.

"I had to bring something different, better energy, better game, so I did.

"I'm very happy that I was able to go through this tough match."

Muguruza has won all five of her meetings with Cîrstea without dropping a set.

She is the first player to move into the round of 16 and will face either Victoria Azarenka of Belarus or Madison Brengle of the United States.

Defending champion Kvitová got revenge over Irina-Camelia Begu with a humbling 6-3, 6-1 win.

The Romanian had beaten Kvitová in St Petersburg two weeks ago but was not able to put up a fight as the Czech won 82 per cent of points behind her first service and converted five of six break points.

The two-time Grand Slam winner will face 16th seed Elise Mertens of Belgium after she overcame Italy's Jasmine Paolini 6-3, 2-6, 7-5.

Estonian fourth seed Anett Kontaveit joined Muguruza in the round of 16 after beating Croatia's Ana Konjuh 6-2, 6-3.

Kontaveit had to face 12 break points in the encounter but fended off 10 to collect her second win in as many meetings against the world number 51.

The victory marks Kontaveit's 10th match won in 2022, joining just four other Women's Tennis Association players in double-digit wins this year.

Kontaveit will face the winner of Kvitová and Mertens' clash.