In a match between two first-time slam finalists, it was the 25-year-old from Brno who came out on top to win 6-1 2-6 6-4 on Court Philippe Chatrier.
Even in this unpredictable era in the women’s game, Krejcikova, ranked 33, stands out as a hugely surprising champion.
She had been pigeon-holed as a doubles specialist having reached world number one in that discipline but always felt she could be a top singles player, too.
Her breakthrough arrived at Roland Garros last year, when a run to the fourth round helped her move into the top 100, and she has not looked back, winning her first WTA singles title in Strasbourg on the eve of this tournament.
With her 12th victory in a row, Krejcikova, playing in just her fifth grand slam singles main draw, will climb to 15th in the rankings after becoming the third unseeded women’s champion in Paris.
They have all come in the last five years, Krejcikova joining 2017 champion Jelena Ostapenko and Iga Swiatek, who lifted the Coupe Suzanne Lenglen last year.
Krejcikova, who will also have a chance to go for the doubles title alongside Katerina Siniakova on Sunday, looked utterly stunned.
She was coached earlier in her career by Jana Novotna who died of cancer in 2017 at the age of 49, and has spoken this week about the impact the former Wimbledon champion had on her career.
Krejcikova said: “It’s really hard to put words together right now because I cannot believe what just happened. I cannot believe that I actually won a grand slam.
“I was going through a really hard time when Jana was passing away I was most of the time with her and I really wanted to experience this because I felt it was going to make me really strong. Pretty much her last words were just enjoy and just try to win a grand slam.
“I know that from somewhere she’s looking after me and all of this is pretty much because she’s looking after me from up there. It’s amazing that I had a chance to meet her and that she was such an inspiration for me. I really miss her but I hope she’s happy right now.”
Krejcikova’s calm approach and neat, contained game carried her to wins over Elina Svitolina, Sloane Stephens, Coco Gauff and Maria Sakkari in the last four rounds, with the semi-final an extraordinary occasion that saw her save a match point.
She looked a little nervous in her opening service game but quickly found her stride and, with Pavlyuchenkova’s big swings betraying her butterflies a lot more, Krejcikova reeled off six straight games.
Pavlyuchenkova, playing in her 52nd slam, had spent the last decade wondering whether this moment would ever happen for her but she needed to put the brakes on quickly to prevent the dream turning into a nightmare.
She did just that, cutting out the errors and beginning to do real damage with her forehand. The Russian saved a break point in the opening game of the second set and from there looked much more composed.
Pavlyuchenkova began to strike winners regularly off both her forehand and backhand and had moved into a 5-1 lead when, after being pulled out wide to her left, she grimaced and grabbed at her left thigh.
She called the trainer at the change of ends, munching a packet of Haribo sweets while she waited before having her leg heavily strapped.
It did not stop her clinching the set in the next game with a backhand drilled onto the line, and Pavlyuchenkova was then made to wait for more than seven minutes while Krejcikova took a bathroom break.
Krejcikova had lost her timing and gave a rare negative outburst after Pavlyuchenkova held in the opening game of the deciding set.
But Pavlyuchenkova began to look uncomfortable on serve and in her movement around the court and Krejcikova moved into a 5-3 lead.
Nerves showed when she missed two match points on Pavlyuchenkova’s serve before double-faulting on the third but the Russian went long on the fourth and Krejcikova held her arms aloft.