Halep next faces either 22nd-seeded Latvian Jelena Ostapenko or Czech Marketa Vondrousova, the world number 61 who ousted 2018 Indian Wells finalist Daria Kasatkina in the second round.
Wawrinka won a taut thriller against 29th-seeded Hungarian Marton Fucsovics 6-4, 6-7 (5/7), 7-5, finally sealing it on his fifth match point after three hours and 24 minutes when Fucsovics lofted a lob long.
"A double break is not ideal against a great server, especially a left-handed server", Williams said, adding that the secret to coming back was "just being in the moment". "He asks me questions and I like to think a lot so it definitely helps me out".
"He seemed like a really good choice (as coach) because I do like to hit with a guy", she said. I think she had a few tight points, and here we are. "I'm really happy I found a way in that second set". Yet the second proved more of a challenge as the German saved four break points in his first service game, then used his momentum to break for a 3-1 lead. The Czech finished with 10 aces to 10 double faults. The relationship I have with this event is very special. "I think maybe from this perspective, I could have, should have made a different decision, but I believe it also taught me some valuable lessons that helped me to create incredible results in the next seven, eight months and get from 22 in the world to number one in the world in less than six months".
"I ended the match in a positive fashion".
"Suddenly, she just started to play better, I started to play worse, and that's why that happen to the third set, which I didn't break up, but I don't know".More news: Ethiopian Airlines plane with 157 people on board crashes minutes after take-off
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"It's always tough to play Venus, for sure".
Admitted Djokovic, who is going for a record sixth Indian Wells title: "I didn't play my best".
Osaka recorded a 6-3, 6-4 victory to avenge the surprise defeat she suffered to Mladenovic at last month's Dubai Tennis Championships.
Ekaterina Makarova pulled off one of her biggest career wins knocking out former champion and 2-time finalist Caroline Wozniacki 7-5, 2-6, 7-5.
There was disappointment, too, for 2011 victor Caroline Wozaniacki, who fell 7-5, 2-6, 7-5 to 59th-ranked Russian Ekaterina Alexandrova. "If I maybe would have served a little bit better, I think things would have gone faster". I was with Novak in Monte Carlo last spring, talking about everything, and I said to [Marian] Vajda, Jelena [Djokovic], Artaldi and Novak himself that it is only a question of time when he will return to the top. "I just loved the battle".