Iga Swiatek gained new-found belief in her own strength after coming through an intense struggle to beat Karolina Muchova and complete her French Open hat-trick.
The 22-year-old Pole cemented her status as the best female player in the world, particularly on clay, with her third title in four years at Roland Garros.
But this was by some distance the hardest of her grand slam finals, with unseeded Czech Muchova battling back from a set and 3-0 down to force a decider.
Muchova twice led by a break in that but Swiatek refused to be beaten, eventually prevailing 6-2 5-7 6-4 after two hours and 46 minutes and crouching down on the clay in tears.
“I’m feeling all these different emotions right now,” said Swiatek. “It’s pretty surreal, everything. But the match was really intense, a lot of ups and downs. Stressful moments and coming back. So I’m pretty happy that at the end I could be solid in those few last games and finish it.
“But Karolina really played well. It was a big challenge. I’m happy and really proud of myself that I did it.
“This one, for sure, it was a little bit tougher in terms of injuries and the pressure, and also coming back to this tournament as a defending champion.
Swiatek is the first woman since Justine Henin in 2007 to successfully defend her title on the Paris clay and joins Naomi Osaka on four grand slam titles – veteran Venus Williams with seven is the only active player to hold more.
Swiatek equals Osaka and Monica Seles, meanwhile, as the only women in the open era to win each of their first four slam finals.
Muchova, a 26-year-old ranked 43, produced the performance of her life to beat second seed Aryna Sabalenka in the semi-finals, saving a match point and fighting back from 5-2 down in the deciding set.
She made a slow start and it looked set to be another comfortable ride in a slam final for Swiatek but from 3-0 in the second set the momentum shifted.
Muchova began to impose her clever game a lot more on the match while Swiatek tightened up, double-faulting to hand her opponent the chance to serve for the set at 5-4.
Muchova could not take her first opportunity but another shaky game from Swiatek gave her a second chance and this time she made it over the line, clinching her third set point after a stunning all-court rally.
Muchova has struggled badly with injuries during her career and it was only last year that doctors told her she might have to give up the game.
She rode her momentum at the start of the decider by moving into a 2-0 lead as Swiatek threatened to implode but the 22-year-old pulled herself together quickly to level.
They exchanged breaks again in the seventh and eighth games and Swiatek regained the ascendancy when she fought off another break point to hold for 5-4.
The pressure of serving to stay in the contest proved too much for Muchova, who made three errors before double-faulting on match point in a cruel end to an absorbing final.
Swiatek said: “I felt pretty confident with my game in the second set but I also knew that it’s only one break. So I needed to stay constantly aware and ready for everything, especially playing against Karolina, knowing that she’s come back from really crazy situations in this tournament.
“In the third set I didn’t want to have any regrets about the second. I just kind of looked forward, and I said to myself, ‘OK, I’m just going to give it all. No thinking, no analysing, just play my game, use my intuition’, and that really helped.”
Muchova was overcome with emotion at the trophy ceremony while Swiatek had to have two goes at lifting the trophy after dropping the lid on the first attempt.
“I honestly felt like I’m holding it with my finger, so I guess all these emotions caused that,” said the Pole.
Muchova was left with mixed emotions, saying: “The feeling is a little bitter, because I felt it was very close, a close match.
“But overall, to call myself a grand slam finalist, it’s an amazing achievement, and for sure big motivation for me to work in the future and to get a chance again to play for these big titles.”