Vandeweghe, ranked number 16, admits that this is her least-favourite surface, but she has still reached the first clay semi-final of her WTA career. She will on Saturday face French sixth seed Carolina Garcia, who constructed a third straight fightback over third-seeded Elina Svitolina 6-7 (4/7), 6-4, 6-2. "At one point in the first set, I wasn't even sure of the score," Vandeweghe said. "Maybe that's the secret."World number one Simona Halep suffered defeat at the Stuttgart Open to Coco Vandeweghe.
— BBC Sport (@BBCSport) April 27, 2018
More: https://t.co/BQrJ3uVcG3 pic.twitter.com/IiwBQyPG3s
The American held her nerve to break early in the second set and added an insurance break for a 5-1 lead and closed out the upset on her second match point a game later when Halep went long with a return. "Clay is still not my favourite surface, it's certainly not my number one," added the American. But with a Porsche 718 Boxster going to the tournament winner along with prize money, Vandeweghe admits she has plenty of motivation to win a first title on the alien surface.Coco #Vandeweghe was unplayable in a straight-sets defeat of Simona Halep - can she summon that same form vs world no. 7 Caroline #Garcia on Saturday?
— Live Tennis (@livetennis) April 28, 2018
More > https://t.co/9FeIwv5gQS pic.twitter.com/qdCaSmrC0U
"I'm one step closer, maybe if I keep it up I can win a new toy to take home to California." Halep lost to an American for the first time since the 2017 Australian Open when she was stunned by Shelby Rogers in the first round). "It was like a flash and I don’t really know what happened during the match," the Romanian said.CoCo Vandeweghe stuns Simona Halep to advance to Stuttgart semi-finalshttps://t.co/BXBukN3qNt pic.twitter.com/Bb449NSXhp
— HT Sports (@HTSportsNews) April 28, 2018
"She served really well and it was really tough to break her. I lost the serve in the first set and then I went a little bit down. "I couldn’t feel the rhythm, I couldn’t feel the game, I missed a little bit too much. She was very strong today." Garcia has made a habit of rallying to beat Svitolina, duplicating comebacks she completed last autumn in Beijing and at the season-ending WTA finals in Singapore.CoCo Vandeweghe finds her game in Stuttgart with win over Simona Halep | https://t.co/oEEsJ8mZsM pic.twitter.com/3qyQN8Lkxy
— TENNIS.com (@Tennis) April 27, 2018
The two-and-a-quarter-hour struggle featured nine aces from Svitolina and 10 from Garcia, who earned her first win of the season over a top 10 player. Saturday's second semi-final will be contested between Estonia's Anett Kontaveit and fifth-seeded Karolina Pliskova of the Czech Republic. Kontaveit needed almost three hours to beat Russia's Anastasia Pavlyuchenkova 7-5, 6-7 (6/8), 6-4 while Pliskova came from break points down in the final game to beat Roland Garros champion Jelena Ostapenko, 5-7, 7-5, 6-4.Garcia on her budding rivalry with Svitolina: “It’s always a pleasure to play against her because there are rallies, no one lets down, and we’re always trying to come back. So it was very important for me.” #PTGP2018
— WTA Insider (@WTA_insider) April 27, 2018
Down goes #1!@CoCoVandey defeats Simona Halep 6-4, 6-1 at @PorscheTennis to continue her amazing run on clay. She faces the winner of Svitolina/Garcia in the SFs! https://t.co/gCCWlXe7IZ
— US Open Tennis (@usopen) April 27, 2018
?: #USOpen 2017 pic.twitter.com/pHZYE8QrIn


