Angelique Kerber is a step closer to becoming world No.1 with a hard-fought win over Barbora Strycova to reach the Cincinnati Open quarter-finals.
The Australian Open champion's 7-6(5) 6-4 victory over the Czech puts the German just three wins from leapfrogging Serena Williams, absent from the event, at the top of the WTA rankings for a first time.
"It's the goal one day to be number one but if it happens and when it happens, whatever," the 28-year-old told ESPN on Thursday, adding that everyone was reminding her how close she was as she tried to block out the thought.
"I would not be putting this pressure on myself here," she said. "I'm just trying to play my best tennis."
Next up for Kerber is Spain's Carla Surez Navarro, who beat Roberta Vinci of Italy 6-1 7-5.
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Elsewhere on Thursday, third-seeded Simona Halep notched her 12th win in a row with a 6-1 6-2 thrashing of Australian qualifier Daria Gavrilova, beating the heat by finishing in 53 minutes.
She now takes on the winner of the match between Agnieszka Radwanska and Australian-born Brit Johanna Konta.
Kerber, enjoying her best season, including a Wimbledon final appearance and silver medal in the women's singles at the Rio Olympics, claims her improved serve and on-court attitude have been key to her rise.
"Mentally, I'm more quiet," she said. "I think I can put the emotion right now in the right place and that helps me to play really good.
"I've had a lot of ups and downs in my career but I'm having the best year of my career and it's still not over," the left-hander said.
"It's amazing what's happened in the last few months ... it's just incredible."
In a hot and humid Cincinnati, Kerber was her usual tireless self against Strycova, scurrying to extend rallies and wearing down her rival.
In the opening set tie-break, she drew errors from her Czech opponent and then closed it out with a precise backhand pass.
Strycova continued to hold her own in the second set but Kerber won the key points, breaking in the ninth game before confidently serving out.
