The unseeded Croatian did not have to be at her best to beat Agnieszka Radwanska, the top seed left in the women's draw, but she maintained the pressure from the back of the court as the Polish third seed had an off day on Philippe Chatrier.
Tomljanovic looked much less at ease in the post-match news conference - "I have never had lights in front of me" - as she explained how she got to know Evert, the Ice Maiden of women's tennis in the 1970s and 1980s.
"I actually have family that lives in the States. When I was little, I would always go and spend my summers there," she said.
"When I was 13, I moved to Florida to live, to train at the Evert Academy, Chrissie and John's place. It always kind of came natural, the English and the accent," said the 21-year-old who lost in qualifying for the last four years at Roland Garros.
"I felt very at home there, I started getting along with Chrissie and John very well. They welcomed me.
"It was all a little better for me to train there and live there if I was going to pursue my tennis career. So when I decided to move, that seemed like the perfect place.
"I'm very fortunate to have her (Evert) in my corner," Tomljanovic said of the American baseliner who won 18 grand slam singles titles.
"Not only she helps me on the court but we actually have a great relationship off the court. We get together when I'm in Boca (Raton). And, you know, she calls, I call her, she calls me.
"It's really great for me to have her as a friend and mentor. She definitely has a ton of knowledge."
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- Agnieszka Radwanska