The Spaniard won with 6–4, 6–4 over the American in the tournament in Tokyo.
The 22-year-old Spaniard is almost unstoppable right now. For Alcaraz, it was the ninth consecutive final and his tenth final in total this year. Only his compatriot Rafael Nadal has previously been in ten finals in a year, 2017.
It has been a fantastic season, without a doubt the best in my career. I have worked hard to experience this, says Alcaraz to the ATP tour's website.
I did not start the year so well, had emotional problems. The fact that I bounced back makes me proud of myself and those around me who helped me.
Among the finals are the Grand Slam tournaments US Open, Wimbledon and French Championships where Alcaraz met world number two Jannik Sinner in all three and only lost in Wimbledon.
Alcaraz is now heading to the major tournament Shanghai Masters which starts on Wednesday.