Simona Halep spoiled Coco Gauff's birthday celebrations on a windy Sunday night, defeating the 18-year-old American 6-3, 6-4 to advance to the Round of 16 at the BNP Paribas Open. The former No.1 will face her compatriot Sorana Cirstea next. 

While Gauff made her tournament debut just last year, Halep is making her 11th appearance. The 30-year-old Romanian has now made the Round of 16 or better at Indian Wells in six of her past eight appearances and will now look to make her fifth quarterfinal in the California desert. 

Facing Gauff for the second time, Halep posted a nearly identical score line as their initial meeting at 2019 Wimbledon, which the Romanian won 6-3, 6-3 en route to her title run. 

"I thought she played well," Gauff said. "I thought I had a lot of chances, a couple break points here and there. Overall I think it was a good match. She has a great level and I knew that coming into it. I think I was making the right decisions, just not executing them."

Tale of the match: On Sunday night, Halep, who won here in 2015, proved the more experienced player in the wind. While Gauff hit 18 winners to 33 unforced errors, Halep kept a much cleaner sheet, striking 11 winners and 12 unforced errors. Halep's serve also proved impenetrable on the night, as she served 77% first serves in and was unbroken for the match, saving all four break points she faced. 

"I'm not scared about the wind," Halep said. "I have never been. Also when I was a kid. As I said I think I played smart tonight because from one side you had to play differently, from the other side a little bit different. So I think I managed very well all the moments."

Halep secured the 6-3 opening set after 38 minutes, but Gauff was not without her chances. With Halep serving with a break in hand at 4-3, Gauff earned triple break-point with a series of big forehand strikes. But Halep coolly worked her way back to deuce with the aid of two errant Gauff backhands that landed long and went on to hold to 5-3. Having dodged danger, Halep immediately broke Gauff for a second time to seal the set.

The second set saw both players manage their service games well, with neither player facing a break point until the final game. With Gauff serving at 4-5, Halep earned triple-match point with two phenomenal forehand passing winners and converted on her third to break for the win.

Now ranked No.26, Halep is now 2-0 vs. Top 20 opponents this season. In addition to her win over No.17 Gauff, Halep also defeated Ons Jabeur en route to the semifinals of the Dubai Duty Free Tennis Championships in February. 

Up next for Halep: It's an all-Romanian derby in the Round of 16, as the two highest-ranked Romanians will face off when Halep faces Cirstea, who came back to defeat Anna Kalinskaya 5-7, 6-1, 6-0. Surprisingly, this will be the first meeting between the two in nearly 12 years. Their last match at any level came in qualifying at 2010 Cincinnati. Cirstea leads the head-to-head 2-1 across all levels, though Halep won their sole meeting on tour at 2010 Marbella. 

"We did [practice] lately a few times, but not very much," Halep said. "It's going to be a big challenge for me. It's just another match. I'm used to playing with Romanians. Of course, it's going to be a tough one. She's a great player."

WTA/Jimmie48

Kerber sails into Round of 16 with Kasatkina win

Former No.1 Angelique Kerber improved to 23-11 in Indian Wells with a dominant performance against a familiar foe, defeating Daria Kasatkina 6-2, 6-1. The win sets up a first-time meeting for Kerber against the highest seed remaining in the draw, World No.4 Iga Swiatek. 

Playing each other for the 10th time in their careers - Kasatkina has faced the German more than any other opponent in her career - Kerber moved to 6-4 against Kasatkina. Despite the windy conditions on Stadium 2, Kerber served at 71% first serves in and played clean, aggressive tennis, hitting 18 winners to 16 unforced errors. In contrast, 23rd seed Kasatkina hit 7 winners to 22 unforced errors. Kerber was able to break serve six times and sealed the win after 63 minutes.

Highlights: Kerber masterclass stops Kasatkina

Kerber's take on the match: "I knew before that I have to play really aggressive against her and to go for it and play my game. It was a little bit windy out there so I was trying to get used to the wind, stepping one step forward and taking the match in my hand. I'm happy with how I played and my performance."

Up next for Kerber: Kerber and Swiatek have practiced numerous times - they share Polish heritage - but this will be the first match between the two. The former No.1 says she'll take some lessons from their practice sessions into the match. 

"I think she really played consistently the last few years, especially last year and the start of this year. She tries to play more aggressive so she has everything that you need to have for a top player. So I think it will be a really tough match, but also it's great to have a match against a top player that I'm playing for the first time. It's not happening so often."

After a slow start to the season, Kerber ready to start again: "I think I started the season a little bit later, two months later than usual, because of all the things that happened," Kerber said. "I didn't have the best off-season because of the Covid situation. Then coming back, being really healthy and being sure and trusting with your body - it was ok, I didn't get a big infection or situation - but now I'm almost trying to come back. Also mind-wise, I'm starting here a little bit fresher. So [I'm] starting the season a little bit here for me."