Top seed Simona Halep rallied from a set down to beat Barbora Krejcikova and book her place in the second round of the Bucharest Open on Tuesday.

Halep is the favourite to regain the title she won in the inaugural staging of the tournament in her homeland two years ago, but the world number five gave an expectant home crowd cause for concern when she lost the opening set.

The 2014 French Open runner-up found her rhythm under the lights in the last match of the day and consigned the unseeded Krejcikova to a 3-6 6-1 6-1 defeat and set up a meeting with Isabella Shinikova. 

Halep, fresh from the agony of losing to eventual runner-up Angelique Kerber in the quarter-finals at Wimbledon, claimed seven breaks after a slow start back on clay.

Last year's runner-up Sara Errani, seeded two, is also into the second round after dumping out Aleksandra Krunic with a 6-3 6-2 victory.

Laura Siegemund, Monica Niculescu, Danka Kovinic and Anastasija Sevastova were the other seeds to reach round two.