Coco Gauff showed her mettle to overcome former world no.1 Naomi Osaka to reach the San Jose quarter-finals, winning 6-4 6-4 at the WTA 500 event.
After an edgy start and being 2-1 down, Gauff went on a blistering run to win 10 of the next 13 games and win the first set 6-4, before going into a 5-1 lead in the second.
Osaka showed her class though, and was able to recover from seven match points, but Gauff ultimately prevailed on the eighth to win the match after an hour and two minutes of play.
The defeat raises more questions about four-time Grand Slam champion Osaka, who has struggled to maintain a degree of consistency while on the WTA tour.
All four of her majors were won in different years and she only has three other career titles to her name.
As for Gauff, this victory continues the upward trajectory in her promising career after showing impressive consistency in the last 18 months. She came within one victory from winning her first Grand Slam in June, only to lose out to current world no.1 Iga Swiatek.
After the victory over Osaka, she said: “Yeah, I’m super pleased. I mean, a straight set win against a champion like her is never easy and I’m glad that I was able to do that.
“I’m still feeling the nerves. I know, it’s a smaller tournament, but I feel that when I play her. I feel that we both want it and that’s I just what I enjoy about playing against her. Because the energy is always at 100 and probably even more.”
Paula Badosa is up next in the quarter-finals on Friday. They have met twice previously, with one victory a piece.
The Spaniard triumphed 6-2 6-2 at Indian Wells last October, but the American prevailed 6-2 6-3 in Doha back in February this year.
Ahead of facing Badosa, Gauff added: “It’s going to be another tough match. I feel like I got a lot of tough matches ahead of me, but that’s tennis.
“I love competing and I feel like these tough matches will make me stronger, win or lose. And I want to play as many top players as I can before the US Open. If you want to win a tournament, then you have to at least beat one of them.”