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The 19 year-old become the second-youngest titlist in tournament history behind Carlos Alcaraz, who lifted the trophy in 2022 as an 18-year-old.

"To be honest I don't know what to say. It feels incredible," Mensik said. "It was probably the biggest day of my life and I did super, which I'm really glad [about], to show the performance and keep the nerves outside of the court before the match. I feel just super happy and I think that the feelings will come later."

The match was delayed nearly six hours by rain in Florida, giving the teen plenty of time to think about the task at hand - trying to stop Djokovic from claiming the 100th tour-level title of his career. But Mensik, who was born in September 2005, when Djokovic was already in the top 100 of ATP Rankings, did not shrink in the moment.

Instead, the Czech rose to the occasion to play the match of his life, producing a scintillating serving performance to become the first player from his country to win an ATP Masters 1000 event since Tomas Berdych triumphed in Paris in 2005.

"It was not the first time I've played against Novak," Mensik said. "There is no harder task in tennis than to beat him in the finals. But of course I felt really great and it's my time, so I just tried to focus on the match like I did before in previous rounds."

This was only Mensik's second ATP Tour final, but he showed few nerves in by far the biggest match of his career. Djokovic has the best tie-break winning percentage on record at nearly 66 percent. But the 19 year-old was the calmer player under pressure, winning both tie-breaks to improve to 7-0 in tie-breaks in the tournament, during which he also eliminated Indian Wells champion Jack Draper in two tie-breaks.

It was clear from early in the clash that Djokovic was struggling with an issue underneath his right eye. The 37 year-old consistently reached towards his eye and used eye drops during changeovers.

Mensik entered the match fresh off a victory against Taylor Fritz, and retained his momentum to start against Djokovic, surging to a 3-0 lead. The 99-time tour-level titlist pushed a forehand wide to relinquish a break in the second game of the match and searched for his game early.

When the Czech hit a backhand up the line into the net to give the break back, the pressure was on from the 40-time ATP 1000 champion. But Djokovic grew increasingly frustrated on return, consistently speaking with his box, including team member Carlos Gomez-Herrera, who urgently signalled his advice.

That frustration carried into the tie-break, in which it was the veteran who cracked. Mensik quickly grabbed a 5/0 lead, showing his athleticism with a backhand smash while allowing Djokovic to make mistakes, both physically and with his shot selection.

The six-time Miami champion made his opponent earn the set, pulling to within a 6/4 deficit. But Mensik closed out the opener with an overhead and turned towards his box to let out a roar.

Djokovic found his rhythm from the back of the court early in the second set, putting plenty of pressure on his young opponent. But Mensik was relentless with his accurate serve. He faced just one break point in the match and won 77 per cent of his first-serve points according to Infosys ATP Stats.

After letting a return go on his first match point, watching Djokovic's shot paint the baseline, Mensik did not panic. Instead he delivered another unreturned serve and fell to the court to celebrate his special moment.

With the victory, Mensik will climb to a career-high No. 24 in the ATP Rankings, passing Jiri Lehecka to become the second-ranked Czech player behind No. 21 Tomas Machac. Two years ago, Mensik was World No. 390.

It was a resurgent week for Djokovic, who began the tournament with a 7-4 record this season. Despite the disappointment of not lifting his 100th tour-level trophy, the Serbian spent his speech during the trophy ceremony praising his opponent.

"This is Jakub's moment — moment of his team, moment of his family. Congratulations, unbelievable tournament," Djokovic said. "It hurts me to admit it, but you were better! In the clutch moments, you delivered the goods [with] unbelievable serving and just a phenomenal effort mentally as well to stay tough in a difficult moment."