San Francisco Frontiers - American qualifier Day on comeback trail at French Open

But the world number 138, who enjoyed a run to the 2017 Indian Wells third round aged 17, has won five successive matches at the French Open, coming through qualifying and now reaching the last 32.

Day downed 20th-ranked compatriot Madison Keys 6-2, 4-6, 6-4 in the second round to earn the first top-20 win of her career.

She is playing in the main draw of a Grand Slam tournament for the first time since the US Open six years ago after suffering a litany of injuries and struggling with mono.

"It was really difficult, because all my injuries... I would be out for three, four months, and I never took a protected ranking, so it was so hard for me to come back," Day said.

"Every time I tried coming back, it just felt like something else would happen. When I started feeling good, it was in 2020 during Covid, and they cancelled all the tournaments and my ranking had dropped to like 600 at that point.

"It was really tough to even try to get into a tournament to try to play... A lot of bad luck and bad timing."

Day has spent the majority of the past few years either sidelined or playing in low-key ITF events, but she never considered hanging up her racquet.

"I don't feel like there was a moment that I really was, like, I don't want to do this. I love tennis, so I've always wanted to do this," she said.

"I've definitely learned that I'm a lot tougher than I thought I was, to just grind my way back like I have.

"A lot of people, I think, counted me out or didn't believe in me anymore or whatever, and I just worked super hard and trusted myself."

Day, who has 1987 men's Wimbledon champion Pat Cash among her coaching staff, also has a Czech passport through her mother and speaks the language fluently.

She counts fellow left-handers Martina Navratilova, who competed for Czechoslovakia and the United States, and Rafael Nadal, who one of her pet dogs is named after, among her idols.

"Rafa I named when I was like nine years old, and just because I was a lefty, and obviously he's one of the best players to ever play the game."

Day will now have her eyes set on a place in the second week, ahead of a last-32 clash with Slovak world number 100 Anna Karolina Schmiedlova on Saturday.

C.Lewis--SFF