But the scoreline did not reflect the fight Cibulkova put up against Great Britain's No.1.

An aggressive performance by the Slovakian put 26-year-old Konta under significant pressure, though she took the first set with two breaks of serve.

WTA Cincinnati
Muguruza thumps Halep in straight sets in Cincinnati final
20/08/2017 AT 19:11

Despite breaking early in the second set, Konta was tormented by Cibulkova who fought hard, and had three break points taking a 4-2 lead, though Konta regained ground to break at 4-4, before serving out her victory.

She will meet Simona Halep in the quarter-finals, who beat number 15 Anastasija Sevastova 6-4 6-3.

Meanwhile, Caroline Wozniacki made it through to the quarter-finals after ending the run of qualifier Ashleigh Barty on Thursday night.

Wozniacki was a comfortable 6-4 6-2 winner as the sixth seed reached the last eight of this tournament for the fourth time in her career.

Barty was impressive early on, breaking Wozniacki to take a 3-1 lead, but it proved a temporary setback for the world number five.

Fourth seed Garbine Muguruza was given more of a workout as she saved match points to battle past American Madison Keys, beating the 16th seed 6-4 3-6 7-6 (7/3).

Eighth seed Svetlana Kuznetsova beat Spaniard Carla Suarez Navarro 6-2 6-4.

Karolina Pliskova remained on track to defend her title at 3-0 up in the first set against Italy's Camila Giorgi, as play was suspended for the day.

Additional reporting by PA Sport.

WTA Cincinnati 3rd Round

Quarterfinal

4-Garbine Muguruza Blanco (Spain) beat 8-Svetlana Kuznetsova (Russia) 6-2 5-7 7-5

Round 3

Sloane Stephens (U.S.) beat Ekaterina Makarova (Russia) 2-6 6-3 6-4

Julia Goerges (Germany) beat 5-Elina Svitolina (Ukraine) 7-5 6-4

1-Karolina Pliskova (Czech Republic) beat Camila Giorgi (Italy) 6-3 4-6 6-0

WTA Cincinnati
Muguruza to meet Halep in Cincinnati final
19/08/2017 AT 18:30
WTA Cincinnati
Pliskova on track to defend Cincinnati title, Venus out
17/08/2017 AT 07:25