Tomljanovic, playing just her second full match in four months after 18 months of injury and surgery setbacks, showed inevitable ring rust after a bright start against 30th seed Dayana Yastremska, eventually being the first of the 11 Australians in singles action at Roland Garros to bow out 3-6 6-3 6-3 on Sunday.
But she was soon followed by Aleksandar Vukic, whose 6-4 4-6 6-3 7-5 defeat to China's Zhizhen Zhang was compounded by an injury concern, and an out-of-sorts Jordan Thompson, whose first grand slam since landing his first ATP tournament triumph ended in a 3-6 2-6 0-6 drubbing by German Maximilian Marterer.
Injured Aleksandar Vukic was struggling with his movement in his defeat. (EPA PHOTO)
Worse was to follow when Chris O'Connell, who's had a solid clay-court season, was reported to have withdrawn from his first-round match against Austrian qualifier Filip Misolic through injury.
Wildcard Tomljanovic's defeat means Australia won't have a woman in the second round in Paris for the first time since 1997 unless national No.1 Daria Saville can pull off an unlikely triumph against 12th seed Jasmine Paolini on Monday.
But Tomljanovic was left putting on a brave face, finding something to be encouraged about in her combative performance against Yastremska, the Ukrainian qualifying sensation who went all the way to the semi-finals of the Australian Open.
But there was an air of realism too from the 31-year-old as she reflected on how difficult it is going to be to clamber back to the form which enabled her to make global news as the final conqueror of Serena Williams en route to the quarter-finals of the 2022 US Open.
"I should not leave this place having any negative thoughts, because it is only up from here, and my body so far has pulled up well, so that is a great thing," said Tomljanovic, who had pulled out of her comeback tournament in Parma last week with a neck injury.
"But it feels like I have a mountain to climb right now. I'm still here. I'm eager. I still have that fire inside me to still keep going , but it definitely has been very challenging.
Chris O'Connell has withdrawn from the tournament after recent injry troubles. (AP PHOTO)
"It's just I feel like I have to almost reprogram my mind and not think about the past, because I'm not the player I was.
"I have to build everything up from the ground again. And that's not easy to accept mentally because you come back straight away and you're like, 'I want to get back from where I was'. But that's gone. A lot of time has passed and I'm here now. It's a process for sure."
Despite the positivity, there was genuine disappointment that she missed a big opportunity here, letting four break point opportunities slip in the second set alone when it felt Yastremska might be wobbling.
"Obviously, very disappointed. I felt like I had so many chances in that second set. It's hard to say you're happy with the way it went, because I lost, but considering everything, I think I played as good as I could have played today," said Tomljanovic.
Vukic had to battle with an adductor problem that he picked up on Friday during his defeat while Thompson just had to battle with his own frustration, banging his racquet down into the clay after one of his 32 unforced errors and capitulating to a final rain-interrupted 'bagel' set in 29 minutes.
O'Connell's withdrawal is another disappointment for the 29-year-old, who had been going well until injury forced him to pull out during a match at the Italian Open.
