The Italian, who claimed the Australian Open in January and followed it up with victory in Rotterdam, put in another scintillating display to down Dimitrov in straight sets at the Hard Rock Stadium.
The 22-year-old become the new world number two with his victory that avenges the defeats he suffered in his previous two tournament finals in 2021 and 2023.
It also means his semi-final loss to Carlos Alcaraz at Indian Wells a fortnight ago remains the only time he has been beaten so far this year.
“It has been a very special week for me, I have faced different kinds of situations on the court and different opponents,” Sinner told Sky Sports. “But I guess I managed the situation well.
“I am very happy to be number two in the world, it is just a number, for me most important is trying to execute my game plan and I managed to do this.”
Dimitrov, who is enjoying a resurgence and ousted Alcaraz in the quarter-final, had the first opportunity to gain the upper hand against Sinner and things might have been different had the Bulgarian not gone wide on an early break point.
That allowed Sinner to take control as he broke in the next game on his way to capturing the first set, clinched via a brilliant backhand winner that brought those in the stands to their feet.
His domination continued, with Dimitrov winning just one more game in the match as Sinner closed things out to claim a second career Masters 01000 title.1
