A gritty comeback earned Simona Halep a milestone victory on Thursday at the Miami Open.

Trailing former Top 10 player Caroline Garcia by a set and a break, 6-3, 3-1, the No. 3 seed won 11 of the last 12 games to secure a 3-6, 6-4, 6-0 victory in her first match in five weeks. 

The one hour, 48-minute victory improved Halep's head-to-head record against Garcia to 7-1, and earned the two-time Grand Slam champion her 400th career WTA main draw victory.

"She started very well and her serve bothered me a lot, the kick. I needed time to get used to it and to get the rhythm," Halep said after the match.

"I felt like in the second set I start moving better. I relax my legs and I could work more with my legs. I needed a little bit of extra power with her because she's a powerful opponent, and I have always to push her back."

Trailing 6-3, 2-1, Halep had her right shoulder attended to during a medical timeout, and revealed that she was struggling with the injury for the duration of the match. 

"I struggled with my serve. I struggled with my shoulder a little bit, so the attention was a little bit on the pain," Halep confessed in her post-match press conference.

"[After that], I started to relax myself, to try to not think about the result, just to loosen up the arm, the body, and then I started actually to move her a little bit more to the forehand. Then I started to get confidence that I can come back.

"When I came here, I didn't feel pain...I was really good. But then I practiced some tough sets with other players and I started to feel again. And now it's getting a little bit worse. But I just feel it when I serve, so I'm trying just to do the recovery as much as possible to serve better, because today it was very slow... I will see how it's gonna hold next days."

"I'm really happy to hear that. It's impressive that I won so many matches on main draw. I have many years there in the top also... when I face some tough moments during the matches, I know what to do. It's from those 400 victories."

- Simona Halep on collecting her 400th WTA main-draw victory.

Up next, Halep will face Latvia's Anastasija Sevastova, who rallied for a 1-6, 6-2, 6-3 win over No. 31 seed Coco Gauff. Trailing by a set and a break at 6-1, 2-1, Sevastova won five games in a row to force a decider, and later rallied from 3-1, 15-40 on serve to seal the victory. 

"I'm really happy that I fought so hard, I didn't start good and somehow I found my game in the second set. She was in front in the third set and somehow I fought back," Sevastova said on-court after the match.

"She serves well and she moves so well, playing like a counterpuncher and it's tough for me to make points. I just had to find another way, and I had to make her risk more."

Halep leads the Latvian, 6-3, in their all-time head-to-head, and assessed the former World No.11 by saying: "Sevastova is cutting the rhythm... You never know what ball to expect from her. Sometimes she plays flat, very flat. Sometimes she can go high, sometimes slices, dropshots. So it's tough to play against her all the time."

"I have to play rallies. I have to stay tough in the rallies and wait for my chances to attack," Sevastova said. "I think it's going to be tough and I think it's going to be close. I like the courts here and it's going to be a good match-up."

2021 Miami Highlights: Halep overcomes Garcia challenge

Also in the evening, No.10 seed Petra Kvitova had no such trouble. Returning to action after her campaign at the Dubai Duty Free tennis Championships ended prematurely due to a right thigh injury, the Czech needed just 64 minutes to dispatch Alizé Cornet, 6-0, 6-4.

In a near-perfect first set where Cornet did not win a point on her own serve, the two-time Wimbledon champion won 24 of 27 points played overall to race into the lead in just 16 minutes. The second set proved tougher, as Kvitova built a 5-2 lead but couldn't close it out on serve, and she ultimately needed four match points to wrap up victory. 

"I think I started pretty well. I was pretty focused and I really know what I should expect from Alizé. In the second set, we played some more rallies... and that was a little bit tougher and wasn't really my game," Kvitova said on-court after the match.

"I feel great. I'm really happy that I can be here competing in Miami again... I had a pretty long run in Doha and the injury on my body was there [in Dubai] but I feel great right now."

In all, Kvitova hit 26 winners to just eight unforced errors to advance to a third-round meeting with No.17 seed and former champion Johanna Konta.