Alcaraz, widely regarded for his mental resilience and ability to fight back under pressure, looked uncharacteristically fragile at the Hard Rock Stadium. In fact, at one stage, he appeared to mentally check out of the contest even before it was decided.

After dropping the first set 3-6 and getting broken early in the second, the reigning Australian Open champion cut a frustrated figure, venting towards his box in a rare moment of visible despair.

"I can't take it anymore. I'm going home, man… I can't take it anymore," he was heard saying, summing up a performance far removed from his usual intensity.

To his credit, Alcaraz briefly rediscovered his level. He fought back in the second set, breaking Korda's rhythm and reeling off five consecutive games after the American had stepped up to serve for the match at 5-4. Yet, even during that stretch, the usual spark - the celebrations, the trademark smile - was missing.

Korda, however, regrouped impressively. The 25-year-old held his nerve in the decider to seal a 6-3, 5-7, 6-4 victory in two hours and 19 minutes, pulling off one of the biggest upsets of the tournament.

Ranked No. 36, Korda became the lowest-ranked player to defeat Alcaraz since Goffin (then No. 55) managed the same feat at this very event last year - a statistic that only deepens the Spaniard's Miami struggles.

Reflecting on the defeat, Alcaraz admitted he was second-best in the key moments.

"It was a tough match, obviously. I think he was incredible today. There were a lot of tight moments that I didn't make the most of, and he was better in those situations," he said.

The loss sees Alcaraz slip to 17-2 for the season, having also suffered a semifinal defeat to Daniil Medvedev at Indian Wells last week.