Coco Gauff entered into the semifinals on Friday after beating Karolina Pliskova 7-5, 6-4 at the Berlin Open.
Czech Pliskova, who was playing her first match against a Top 20 player this season, started the second set with a 2-0 lead, but Gauff quickly pulled back on serve with a passing winner.
At 5-4 in the opener, Pliskova finished a rally with a brilliant forehand winner to collect two set points. But Gough used excellent serves and clever slices to clear away two more along with both of them before catching for 5-5 after 15 minutes of challenging play.
The Greek player will face Belinda Bencic in the semifinals.
