Ekaterina Alexandrova booked her place in the last 16 of the Internationaux de Strasbourg after a straight sets win over Lauren Davis on Sunday.

Third seed Alexandrova claimed a comfortable 6-1 7-5 win in 80 minutes to setup a meeting with Clara Burel, who clinched a surprise 6-3 6-1 win over Varvara Gracheva despite being ranked 56 places below her opponent.

Kristyna Pliskova was knocked out following a hard-fought 7-5 6-4 loss to Alize Cornet.

Cornet's reward is a tie with eighth seed Magda Linette, who triumphed 6-2 6-0 in a one-sided match against Nao Hibino.

Petra Kvitova recovered from a poor start to beat Magda Linette in the first round of the Internazionali BNL d'Italia on Monday.

Linette took just 31 minutes to win the first set in Rome, but world number 10 Kvitova responded superbly to win 1-6 6-0 6-2.

Two-time grand slam champion Kvitova racked up 16 unforced errors in the first set, yet rallied like the great competitor she has proved to be for so long to ensure she will face Vera Zvonareva - conqueror of Christina McHale - in the second round.

The 11th seed from the Czech Republic said: "The first set I started very badly. I was missing almost everything. On the court... [the ball] was bouncing everywhere as well. A little bit windy. I just had to get used to probably everything.

"The beginning of the second set when finally I held my serve and broke her serve, I think since then it was much, much better."

French Open champion Iga Swiatek advanced when Alison Riske retired at 5-4 down in the first set due to a recurrence of a left foot injury.

Swiatek, who will take on Sloane Stephens or Madison Keys in the second round, made 18 unforced errors but had won four games in a row from 4-1 down when the American was unable to continue. 

Coco Gauff battled past Yulia Putintseva 7-5 4-6 6-4 to set up a meeting with 17th seed Maria Sakkari  - who fended off qualifier Polona Hercog 7-6 (8-6) 3-6 6-2.

Amanda Anisimova will do battle with Elina Svitolina, a winner of this tournament twice, after defeating Wang Qiang 7-5 6-3. Jessie Pegula, Jennifer Brady and Petra Martic were among the other winners on day one.

Top seed Ons Jabeur advanced to the last 16 at the MUSC Health Women's Open, while Magda Linette was a casualty on Tuesday.

Jabeur – who reached the semi-finals of the Volvo Car Open – made a winning start at the WTA 250 event after toppling Stefanie Vogele 6-4 6-1.

The Tunisian won 88.9 per cent of her first serves to set up a clash with qualifier Alycia Parks – the latter eased past fellow American Grace Min 6-1 6-4.

However, second seed Linette crashed out at the hands of in-form Colombian Maria Camila Osorio Serrano.

Osorio Serrano, who claimed her maiden singles title at the Copa Colsanitas in Bogota last week, upstaged Linette 6-3 4-6 7-5.

Elsewhere, 15-year-old wildcard Linda Fruhvirtova – in just her second WTA main-draw appearance – progressed 6-2 6-7 (7-9) 4-4 after fourth seed Alize Cornet retired in the final set.