CINCINNATI, OH, USA - No.11 seed Dominika Cibulkova survived a stern test in her first match at the Western & Southern Open, needing three sets to edge past the big-hitting Ana Konjuh.

After splitting two very close opening sets, Cibulkova pulled away in the third, needing two hours and 20 minutes to come back from a set down and secure the 5-7, 7-5, 6-2 victory.

“I had to dig really deep because she was hitting really hard balls today and she wasn’t hesitating for a second,” Cibulkova said in her on-court interview.

“It was not easy for me to play, I didn’t get my rhythm, but I battled through it and I’m happy to be in the second round.”

This time last year, 19-year-old Konjuh was ranked World No.98 and failed to qualify for Cincinnati. But the young Croat has seen career-best results all season long - including a win over Cibulkova at Wimbledon - and rising to a career high ranking and breaking into the Top 20.

She showed her quality against the reigning WTA Finals champion, staying aggressive against Cibulkova and finding her range on the big points. With both players known for their power at the baseline, the match was punctuated by breaks of serve - clocking in at 12 in total between the two.

In the first set, it was Konjuh who came out on top after five breaks - the 19-year-old surged ahead twice and both times Cibulkova roared back, even breaking Konjuh as she served for the set. But Konjuh surged head again and finally shut out CIbulkova, dodging the tiebreaker to take the opening set.

The double faults and first-serve woes started to creep into Konjuh’s game in the second, giving Cibulkova plenty of vulnerable deliveries to pounce on. It took four consecutive breaks of serve before Konjuh finally held, leaving them locked at 3-3. Cibulkova continued to pile on the pressure and finally broke through in the very last game, taking the decisive break into a third set.

But while Cibulkova only grew stronger and more accurate in the third, Konjuh started to show signs of wear. Her unforced error count grew - she’d end the match with 71 in total against 41 winners, against Cibulkova’s 21 winners and 37 unforced errors.

Konjuh couldn’t keep up the attack as Cibulkova broke twice and took her spot in the second round after a grueling two hours and 20 minutes in the Cincinnati heat.

“I was so focused on the game that I knew I was sweating like crazy but I didn’t realize it was so hot,” Cibulkova said.

“I was just focused on every single ball because she could break at any second.”

The Slovak has never seen big success in Cincinnati - last year’s round of 16 appearance broke a six-year streak of first and second round exits - but after surviving a tough opener she’s keen to build on today’s victory.

Her next opponent will be the winner between Alize Cornet and CiCi Bellis.