After Maria Sharapova was an early casualty at the Qatar Open, normal service was resumed on a good day for the seeds in Doha.

The renewal of Garbine Muguruza's coaching relationship with Conchita Martinez got off to a strong start as she defeated Duan Ying-Ying.

Petra Kvitova extended a hugely impressive winning streak, while the likes of Caroline Garcia, Johanna Konta and Madison Keys were in fine form as they all kept alive their hopes of winning the WTA Premier 5 tournament.

MUGURUZA & MARTINEZ MAKE WINNING START

Having been in her corner during Muguruza's Wimbledon triumph last year when regular coach Sam Sumyk was absent as his wife was expecting their first child, Martinez is back in the Spaniard's team as she tries to revive her fortunes after a disappointing 2018 to date.

Muguruza lost to Hsieh Su-wei in the second round of the Australian Open, but a shock was never on the cards against Duan, the two-time grand slam champion winning 6-3 6-4 to reach the third round.

She needed eight match points to seal the win and said afterwards: "It was a very tough match. It doesn't matter how many match points I had, I won! That's the important part, and I'm so happy because it's been so long since I've competed. It's good to have a victory."

Muguruza will face either Elise Mertens or Sorana Cirstea in the next round. Mertens beat Timea Babos in three sets while Cirstea overcame Maria Sakkari.

EIGHT IN A ROW FOR KVITOVA

After winning in St Petersburg two weeks ago, Kvitova made a stunning start as she dispatched wildcard Cagla Buyukakcay in under an hour.

The Czech made it eight victories in a row, coming through 6-3 6-0 and hitting 34 winners and only 15 unforced errors in the process.

She now faces a second-round meeting with Agnieszka Radwanska and said of her upcoming encounter with the former Wimbledon finalist: "I know that she's pretty tricky. And that's all I can really say, nothing more. She can play unbelievable. So I need to be ready for that."

GARCIA ENDS CIBULKOVA BATTLE WITH BAGEL

Seventh seed Caroline Garcia was pushed to a third set by Dominika Cibulkova and will have expected a tough fight from the 2014 Australian Open finalist in the decider.

But the Frenchwoman instead raised her game and dished out a bagel to complete a 6-3 6-7 (3-7) 6-0 victory and reach the third round, where she will face either Kristina Mladenovic – a victor over Peng Shuai – or qualifier Anna Blinkova.

Konta, seeded 10th, hit her stride after a shaky first set to see off Bernarda Pera 7-6 (7-5) 6-1 and Keys needed only 55 minutes to defeat Wang Qiang 6-1 6-4.

Ninth seed Julia Goerges, 13th seed Anastasija Sevastova and 14th seed Magdalena Rybarikova all progressed to the second round by beating Lucie Safarova, Donna Vekic and Fatma Al-Nabhani respectively.

WITTHOEFT SET FOR WOZNIACKI TEST

Carina Witthoeft thrashed German compatriot Tatjana Maria 6-3 6-0, her dubious reward a clash with world number one and Australian Open champion Caroline Wozniacki.

Elsewhere in the draw there were wins for Carla Suarez Navarro, Samantha Stosur, Marketa Vondrousova, Barbora Strycova, and Alize Cornet.