Ranked as high as number two in the world in 2022, the Spaniard has plummeted down the table in recent months due to a string of injuries, including the back issue that has proved especially hard to overcome.

Having made steady progress since returning to the tour in January after pulling out of last year's Wimbledon, she earned a battling 7-6(6) 4-6 6-4 victory to dump out Eastbourne champion Kasatkina in the third round.

"It's not my first time in a second week (of a Grand Slam), but it's the most special one. I'm really proud of myself. I've been struggling a lot with injuries, and it's been now a long time that I wasn't in a second week," Badosa told reporters.

"Last year here I had to retire. I was on the couch and watching the tournaments from home. This year when I started, I didn't know what was going to happen."

Badosa was told by doctors earlier this year that it would be complicated to continue her career, but she persevered with the help of cortisone injections.

"At the bottom of my heart, I wasn't accepting it. I was, like, 'I'm going to continue no matter what'. That's also what made me the player I am, that I always want more," she said.

"I'm always going to fight, however difficult that moment is, you know.

"Of course, there are some moments that there's pain, and you don't really know what to do. You a feel a bit lost. But I didn't care. I remember telling to my team that I was going to play with pain."

Badosa made the third round of the French Open last month before reaching the quarter-finals at Bad Homburg to break back into the top 100.

"I've always been tough mentally and a fighter, so I was going to do it anyway. So for me, I'm very proud that I've been through all of this," Badosa said.

"And now I'm again in the fourth round and playing at a good level, because sometimes when I came back (I was) struggling so much, my level wasn't there.

"I felt so far away. Now, seeing myself back at it, it means a lot."