In the five months between the end of the Australian Open and the start of Wimbledon, Barbora Krejcikova won just three singles matches. She had fallen into a brutal cycle of illnesses, injuries and pitiful form and, at times, it seemed like there was no way out. She arrived in SW19 with low expectations, still just trying to find her feet again.

But things can change so quickly in tennis; just a few key wins can build enough confidence for a player’s game to suddenly flow as if nothing had ever been wrong. That process has played out in full for Krejcikova over the past fortnight and by the time she arrived in her first Wimbledon singles final, she was ready.

Related: Krejčiková continues Czechs’ Wimbledon success – and pays tribute to her mentor

After seemingly heading towards being a one-sided rout, the final developed into a tense, brilliant tussle with so much heart before the Czech 31st seed steadied herself and held off a spirited comeback from Jasmine Paolini to close out a 6-2, 2-6, 6-4 win over the No 7 seed.

“I think nobody believes that I got to the final and I think nobody is going to believe that I won Wimbledon,” Krejcikova said. “I still cannot believe it.”

Three years after her shock run to the Roland Garros title, Krejcikova is now a two-time grand slam singles champion. She has already built one of the great doubles – including mixed – résumés of this generation and few active tennis players, male or female, can match her overall grand slam trophy cabinet: Krejcikova is now a 12-time grand slam champion and a three-time Wimbledon champion.

“It’s great that I’m a two-time major champion,” said Krejcikova. “It’s something unbelievable. On the other hand, I’m still the same person. I still love tennis very much. I still want to continue playing tennis well and fight for other tournaments.”

The only other meeting between these finalists had come in the first round of the 2018 Australian Open qualifying tournament, which was won comfortably by Krejcikova although she didn’t reach the main draw. It is a reflection of their late-blooming careers – they are both 28 and were born 17 days apart – that this occasion marked the first time that a grand slam qualifying match had been replicated in a major final.

This time, Krejcikova burst out of the blocks determined to take the first strike immediately and dominate with her forehand while serving brilliantly. Paolini mixed in drop shots, sharp forehand angles and she tried to disrupt Krejcikova’s game but each time she was under pressure, the Czech demonstrated her phenomenal hand skills, resetting countless exchanges with skidding defensive slices before working her way back on top of the point. She eased through the ­opening set.

Instead of crumbling under pressure, Paolini began the second set determined to impose her game on Krejcikova as the Centre Court crowd forcefully cheered her on throughout. She injected more pace into her ground strokes on both wings, found greater depth and began to throw herself into her forehand. The momentum shifted immediately and as the Italian took the initiative, nervous errors flowed from Krejcikova’s racket as a third set beckoned.

With both the momentum and crowd firmly behind her, Paolini opened the third set launching herself into forehands, dominating the neutral rallies and targeting the unravelling Krejcikova backhand. The Czech made up for her tense shot-making by serving immaculately and she built up her confidence by ­breezing through her service games.

By the middle of the third set, Krejcikova had regained enough ­confidence to make her move at 3-3 on Paolini’s vulnerable serve. She finally took back the initiative in the neutral rallies, dominating with her forehand again as she snatched the break.

The brilliant battle ended in a breathless final game as Krejcikova wrestled with her nerves and her backhand, while Paolini fought until the death. After nearly two hours, Krejcikova closed the door on a ­spectacular triumph.

Although Paolini was extremely disappointed, she recognised her undeniable progress. After spending most of her career outside the top 50, this year – which took off with her winning the Dubai 1000 in February – her performances have taken her to heights she could have never ­imagined, with back-to-back major finals at Roland Garros and Wimbledon. “It’s been an incredible year,” she said. “I’m ­enjoying. I hope to continue like that with this level of tennis. I’m going to try to work to keep this focus, this level.”

Related: Barbora Krejcikova v Jasmine Paolini: Wimbledon 2024 women’s singles final – live

This is, of course, a poignant full-circle moment for Krejcikova. She was still hundreds of ranking spots from even competing at Wimbledon in 2014 when she knocked on the door of her compatriot Jana Novotna, the 1998 singles champion, in search of guidance from a home legend.

That meeting would spawn an instant friendship, as Novotna quickly decided to travel and work with her, coaching her until shortly before she died in November 2017. Twenty-six years after Novotna finally won Wimbledon, Krejcikova was tearful as she saw her name engraved on the All England Club’s honours board close to Novotna’s.

“The only thing that was going through my head was that I miss Jana a lot,” she said. “It was just very, very emotional. Very emotional moment to see me on a board right next to her. I think she would be proud. I think she would be really excited that I’m on the same board as she is because Wimbledon was super special for her.”