The 28-year-old Croatian had plenty to celebrate as she reached the second week of a major for the first time by eclipsing Estonian Kaia Kanepi 5-7 6-2 6-4.
Martic admitted she feared that she may never experience the joys of going deep into a major after stalling in the fourth round on four occasions - twice at Roland Garros and also at the Australian Open and Wimbledon tournaments.
"Well, it was tough mentally for me today, especially because I was stopped four times before in the fourth round, so it really felt like I was doubting whether I was ever going to get through that fourth round," 31st seed Martic, who made her Grand Slam debut at Roland Garros in 2009, told reporters.
"That was close, two years ago. I was two points away," she added recalling her last-16 French Open encounter with Ukraine's Elina Svitolina.
"Didn't happen. Today it played a role in my mind. It was not always easy to focus on my game, but I really just tried to fight as hard as I could, and thank God, I finally made it."
This time she believes she came better prepared thanks to her new coach, Sandra Zaniewska, a former tennis professional.
"When I started working with her, everybody was doubting my decision," said Martic, who is a year older than her coach.
"People even laughed at it. But I always knew, I heard this girl talking about tennis and I knew she knows what she's doing.
"So it was not easy for me to make that move. It was a pretty bold move, and I was a bit shaky at the beginning, because I also wanted to prove that I did the right thing."
Now Martic has a real chance of going even deeper in the tournament as she next faces Czech teenager Marketa Vondrousova, whom she beat in the final of the Istanbul tournament in April.
(Reporting by Julien Pretot; Editing by Pritha Sarkar)
