British number one Johanna Konta says she stopped herself "overthinking" in the win that sent her into round two of the French Open for the first time.
Konta, seeded 26th, won 6-4 6-4 against German world number 147 Antonia Lottner.
She had lost her four previous first-round matches at Roland Garros.
"Obviously, it's nice to have won a main-draw match here," the 28-year-old said. "But I have never doubted my ability on the surface."
Konta took her first match point when Lottner could not return a thumping backhand, setting up a second-round match against American wildcard Lauren Davis.
The former Wimbledon semi-finalist is the first Briton through at Roland Garros, with men's number one Kyle Edmund meeting France's Jeremy Chardy later on Monday.
Compatriots Cameron Norrie and Dan Evans play their opening matches on Tuesday.
End of Konta's barren run
Konta, who won qualifying matches at Roland Garros in 2013 and 2014, said her barren main-draw run had not been playing on her mind.
Yet the importance of finally getting over the line against Lottner - ranked 121 places below and making her Roland Garros debut - was abundantly clear.
"It is in human nature to have doubts and negative thoughts. There are plenty of stats on that, that we have more negative thoughts than positive ones," she told BBC Sport.
"But I think it was more about me trusting my habits, giving me the space to miss and the space to just play."
On paper, it should have been a formality given the 28-year-old's superb clay-court season leading up to the second Grand Slam of the year.
Konta reached WTA finals at the Morocco Open and the more prestigious Rome Masters, racking up wins against Grand Slam champions Sloane Stephens and Venus Williams, plus world number four Kiki Bertens, on the way.
Rediscovering a potent first serve has been key to her recent success, although it deserted the Briton in a strange opening set where there were seven breaks of serve.
A first-serve percentage down at 62% was hampered further by only winning 56% of these points, although it proved to matter little because of equally erratic serving from the other end.
The second set was completely contrasting.
Apart from Konta being unable to convert two break points for a 3-1 lead, chances were rarely offered as both players regained composure in their service games.
Out of nowhere, Lottner rustled up a pair of break points for a 5-4 lead, only for former world number four Konta to save them with a big first serve followed by a backhand winner.
Lottner saw another chance disappear with an unforced error and that proved vital as Konta - backed by a typically strong British support in Paris - held before breaking for victory in what proved to be the final game.
"I had to trust myself in giving me some opportunities, my opponent was tricky because she didn't give much rhythm," Konta added.
"There was a lot of time to think, or overthink, but I did a good job of not doing that."
Analysis
BBC tennis correspondent Russell Fuller
However well Johanna Konta has been playing on clay this year, four previous Roland Garros first-round defeats were bound to play on her mind.
She was not at her most fluent on serve, and was broken three times in the opening set.
But when the chips were down, and Konta was facing two break points at 4-4 all in the second set, her resolve strengthened - and she was soon back in the locker room.
A second-round match lies ahead with Lauren Davis, who is currently outside the world's top 100. But the 25-year-old is in the draw because of recent performances on clay, which earned her the wildcard reserved for an American player.
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