Hercog won the first set against Gauff, and she actually was match point away in the second set as well, up 5-2.
Gauff's serve was under constant threat from the start, saving early break points, before it was finally breached at 4-3 and Hercog took the first set thanks to another weak service game where the American sent down three double faults. But can the brash 15-year-old live up to her fast-growing reputation and do the unthinkable?
The 15-year-old, nicknamed Coco, has gripped tennis fans all over the world, since beating her idol and five-time champion Venus Williams in her opening game of the tournament. From there, Gauff worked her magic in the third and final set, pulling off the improbable win. She received a wildcard into the qualifying draw, and en route beat qualifying number one seed and 94th ranked Bolsova to register her first win against a top 100 player. He then broke for a 2-1 lead in the fourth and sealed the victory with a service victor on his first match point.
Next up for the American is a clash with former world No 1 Simona Halep, who beat Belarusian Victoria Azarenka 6-3 6-1 in 66 minutes on Centre Court. She beat five-time Wimbledon champion Venus Williams in the first round and 2017 semifinalist Magdalena Rybarikova in the second.
'I'm just super relieved that it's over.
Even before Wimbledon, Gauff looked like a future star of tennis.
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The Windies have made two changes, with opener Evin Lewis and paceman Kemar Roach in for Sunil Ambris and Shannon Gabriel. He leaves with just six wickets at an average of 69 and an economy of 5.79, and just 105 runs in nine innings.
Polona Hercog ousted the 17th seed Madison Keys 6-2, 6-4 in the second round to quality for the third round at Wimbledon.
With play on Centre Court and No. 1 Court continuing into the evening Friday, the All England Club announced that the first-round match in mixed doubles for the Williams-Murray pairing would be postponed to another day. "Even when I was down match point they were still cheering me on".
According to the U.S. Tennis Association, Gauff is the youngest player to reach the third round of Wimbledon since 1991.
"There are a lot of factors that go into that, but I think as long as she stays happy and is able to continue to play well, I think she ll be fine".
Today, Gauff took on Polona Hercog and was on the brink of elimination twice.
The victor of this match will set up a tough tie against either 2018 French Open champion and seventh seed Simona Halep, or two time Australian Open champion and Wimbledon semi-finalist Victoria Azarenka.