Varvara Gracheva notched her biggest career win by ranking with a 6-2, 6-2 upset of World No.5 Ons Jabeur in the second round of the Miami Open on Friday.

Currently ranked at a career-high World No.54, 22-year-old qualifier Gracheva added another win to a breakthrough season by topping the No.4 seed Jabeur in 1 hour and 11 minutes. Jabeur received two visits from the medical trainer during the second set.

"The plan was, of course like all matches, to be as stable as possible, to try to make her work as much points as possible, and of course wait for comfortable ones to attack," Gracheva said on court, after her win.

Read more: Andreescu overcomes Sakkari in three hours in Miami

Gracheva's surge continues: Gracheva has posted a number of milestones during the first quarter of 2023. She made her first career WTA singles final at Austin last month, contributing to her current career-high ranking as she knocks on the door of the Top 50.

Gracheva also grabbed her first two Top 10 wins this year, beating No.8 Daria Kasatkina at both the Australian Open and Indian Wells. Victory over Jabeur increases that total to three Top 10 wins, with this result marking her first Top 5 win. 

On Friday, Gracheva had 11 winners to nine unforced errors, and a 5-for-6 break point conversion rate. This is already Gracheva's 13th main-draw win this season; by comparison, she only won eight main-draw matches in all of 2022.

"I just probably caught this wave where I'm stable, where I always have a chance to play my game, be aggressive, cause troubles for the others by the game style," Gracheva said, regarding her hot streak. "Just try to keep rolling on this way."

Jabeur comeback interrupted: Jabeur, who reached World No.2 and two Grand Slam singles finals last season, has only played three matches since the Australian Open in January, as she comes back from a knee injury.

Tunisia's Jabeur had to miss the entire Middle East swing in February while she recovered. Jabeur went 1-1 at her return in Indian Wells, falling to Marketa Vondrousova for the second time this season.

Against Gracheva on Friday, Jabeur was undone by 13 unforced errors in the first set, with only three winners in that set. In the second set, a struggling Jabeur received visits from the physio at 3-0 and 3-2.

Jabeur had a brief renaissance when she found some magical net play to earn her only service break of the day after the medical time-out at 3-0. But more miscues allowed Gracheva to break back for 4-2, and Gracheva found some fiery forehands and dictated for the rest of the clash.

Kvitova dispatches Noskova

In the same quarter of the draw, No.15 seed Petra Kvitova also booked a third-round spot on Friday. Two-time Wimbledon champion Kvitova of the Czech Republic raced past her 18-year-old countrywoman Linda Noskova 6-3, 6-0 in just 67 minutes.

Highlights: Kvitova def. Noskova

In their first meeting, Kvitova converted six of her 10 break points to oust World No.51 Noskova, a finalist at the Adelaide International 1 earlier this year.

"It’s always challenging to play somebody who is young and coming up, she’s had great results," Kvitova said afterwards. "Especially a fellow Czech player, it’s always a bit tougher to play a Czech.

"But I think I managed to have a good level of my tennis. I tried to play aggressive, which I think was really the key. … She can play really aggressive and fast too, so I knew that I’d have to be the first player that’s going to push her a little bit."

Making her 13th appearance in the Miami Open main draw, Kvitova has yet to progress beyond the quarterfinals, which she has reached three times at the event.

Next up for Kvitova will be a third-round clash against No.22 seed Donna Vekic. Kvitova leads their head-to-head 3-1.