Simona Halep is the 2018 French Open champion with a three set win over Sloane Stephens.
Amid some spellbinding rallies Stephens, the US Open champion, clinched a solitary break to take the first set.
Romanian Halep, 26, is the world number one but was still hunting a first grand slam title, four years after her first appearance in the final at Roland Garros.
Widely regarded as having played too defensively in her final defeat by Jelena Ostapenko 12 months ago, Halep was the aggressor in the early stages.
But she could not break the defence of the composed Stephens and it was the American who secured the break for 3-1.
Halep ensured Stephens would have to serve the set out, and forced a break point of her own, but the 25-year-old held her nerve to take it 6-3 in 42 minutes.
Stephens then looked to have taken control of the match with another break at the start of the second set.
But Halep, stung into action, levelled things up in the fourth game, breaking Stephens to love as the first chinks in the American's armour appeared.
A hold to love meant Halep had hit eight unanswered points, and another break followed as Stephens' levels dipped for the first time in the match.
But just as the set was slipping away from Stephens, a series of unforced errors by Halep gifted her the break back at 4-4.
Yet Halep survived a pressurised service game and then turned the screw, eking out a break point which Stephens planted wide to force a deciding set.
A hold and a break later and Halep was ahead for the first time in the match, with Stephens' error count rising and rising.
A second break followed, the result of a stunning rally with both players slugging it out at the baseline before charging into the net, Stephens blinking first.
Halep was closing in on the title she craved so much, while Stephens was wilting fast, and a comfortable hold made it 5-0.
Stephens forced Halep to serve it out, and as yet another chorus of 'Simona' rang around Court Philippe Chatrier from the vast Romanian contingent, she did just that, sealing the title with an unreturnable serve before covering her face with her hands in disbelief.