Wimbledon champion Garbine Muguruza suffered a shock three-set defeat in her opening match in Indian Wells against world number 100 Sachia Vickery.
The Spanish third seed led by a set and 3-0 but went down 2-6 7-5 6-1 to the American qualifier, who goes on to face Japan’s Naomi Osaka in round three.
“I’ve just worked so hard for so many years and I’ve been so close,” said 22-year-old Vickery.
“This is just the most amazing night of my life and I couldn’t be happier.”
Vickery scored one of a number of shock wins in Indian Wells on Friday, with teenagers Amanda Anisimova, Aryna Sabalenka, Marketa Vondrousova and Caroline Dolehide all making progress.
Youth also held sway on the men’s side as 17-year-old Canadian Felix Auger-Aliassime claimed his first ATP main-draw win, and 19-year-old Australian Alex de Minaur his first Masters 1000 victory.
De Minaur won a gruelling encounter 3-6 7-6(3) 7-6(5) against Germany’s Jan-Lennard Struff, and Auger-Aliassime saw off compatriot Vasek Pospisil 6-2 7-6(4).
The pair join fellow teenagers Denis Shapovalov and Stefanos Tsitsipas in round two.
Top seed Simona Halep made it through in straight sets, and in-form Petra Kvitova needed more than three hours before also progressing, but Muguruza could not join them.
The Spaniard looked in complete command when she led Vickery 6-2 3-0 40-0, but would end the match with 45 errors to 22 winners as her resistance crumbled.
— WTA (@WTA) March 10, 2018
Vickery, at her highest-ever ranking of 100, dominated the second half of the contest, reeling off the last five games in a row to secure a sensational win.
“I just tried to fight every point and hang in there,” she said.
“The crowd was so amazing and got behind me, and the atmosphere really helped me even though I was feeling it a little bit physically.”
13 September 2018
Naomi Osaka continued her round of appearances on US television, interviewed on The Ellen ... More
12 September 2018
Rafael Nadal’s withdrawal because of injury has left France strong favourites to beat Sp... More
19 September 2018
For all the talk of teenagers no longer being able to break through on the women's tour du... More