Carlos Alcaraz has become the youngest winner of the Miami Open. AP
The 11th-ranked Spaniard, seeking his third title in 2022, improved to 19-3 this season. He was coming off an early exit in Monte Carlo after winning in Rio de Janeiro and Miami.
The 18-year-old Alcaraz hadn't played in Spain since losing to idol Rafael Nadal in the round of 32 of the Madrid Open last May.
``It was tough to keep up with the score in the second set,'' Alcaraz said after beating his 71st-ranked opponent from South Korea. ``I think he started to play really well. And then I (started) very well at the third.''
The fifth-seeded Alcaraz will next face countryman Jaume Munar, who defeated ninth-seeded Nikoloz Basilashvili 6-1, 6-4.
Top-seeded Stefanos Tsitsipas was 5-1 up in the first set when his match against 44th-ranked Ilya Ivashka had to be suspended overnight because of rain. The match will continue on Thursday morning.
Third-seeded Felix Auger-Aliassime earned his second clay-court win of the year by defeating Spanish qualifier Carlos Taberner 6-1, 3-6, 6-4 in the second round, improving to a career-best 15-4 record in 2022 after winning his maiden title in Rotterdam and reaching the final in Marseille.
``It was unfortunate that I lost my rhythm a little bit in the second set, lost my serve too many times, but I credit him also for defending well, showing a great level for a clay-court player,'' Auger-Aliassime said.
He will next face American Frances Tiafoe, who got past Bolivian qualifier Hugo Dellien 7-6 (3), 6-1.
Eighth-seeded Pablo Carreno Busta defeated qualifier Bernabe Zapata Miralles 6-3, 6-3 in an all-Spanish match, while Marton Fucsovics beat veteran Federico Delbonis 6-2, 6-1.
Alex de Minaur defeated Ugo Humbert 6-3, 4-6, 6-3.
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