Martic's win in particular was impressive after potential injury woes at Palermo last week which saw the No.2 seed struggle against Anett Kontaveit. But she bounced back in style seeing off Varvara Gracheva 7-6 (2), 6-3 in just under two hours.
She hit 20 winners to 19 unforced errors and maintained a 100% success rate behind her dropshots taking nine rallies in the process. Gracheva made too many mistakes in the tie hitting 29 unforced errors to 21 winners.
In the latter half of the match from 4-2 in the second set, she only conceded two more points on her serve taking her first match point to set up a tie with Kristyna Pliskova who saw 15-year-old debutant Linda Fruhvirtova in a 6-2, 7-5 victory.
While for Mertens it was a 7-5, 4-6, 6-3 win over Jasmine Paolini in a tough first win for the Belgian after losing in Palermo. Next up will be Camila Giorgi or Marta Kostyuk.
Anastasija Sevastova on the other hand is out losing to Irina Begu with the latter despite playing with a hand injury easing through in a 6-2, 6-2 win which means the ninth seed is out.
Anastasia Pavlyuchenkova is also out after being seen off by Arantxa Rus 7-5, 6-2 in just under two hours with the World No.30 falling at the first hurdle.
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