Simona Halep returns from afar to reach the third round

The Wimbledon champion broke the penultimate serve in the penultimate Group C game to reach the third round after a two-hour match.

Halep, 27, ranked fourth in the world runner-up on three occasions, most recently last year in the final lost to Dutch Kiki Prentz.

The French Open champion will meet in the next round with the winner of the confrontation, which will meet American Madison Keys with Russian Daria Casatkina.

Halep was injured in last week's quarter-final against Toronto's Mary Bozkova.

'It was a very, very difficult game,' Halep said after the match. 'Ekaterina performed well and hit the balls hard.'

'It was hard for me mentally to get back into the competition after I played injured last week. But I didn't feel pain, I needed some time to get into the atmosphere.'

In other results, Australia's top seed Ashley Barti eliminated her Russian counterpart Maria Sharapova 6-4, 6-1 in a match between two former professional players.

The French Open champion beat the Grand Slam winner on five occasions and the 2011 Cincinnati champion for the second time this season, having also excluded her from the Australian Open earlier this year.

In the third round, Barti will meet the winner of the clash between Poland's Iga Sviatik and Estonian Annette Contavit.

Ninth-seeded Ukrainian Elena Svetolina, in turn, reached the next round by beating Belgian Elise Mertens 6-4, 6-1.