After exchanging early breaks, neither player was really able to impose themselves on the match with both having to work hard at times to hold serve.
However, in the tie-break, Sinner upped his first serves and after squandering the first of two set points, an Alcaraz double fault gave him the initiative in the match.
Sinner started the second set sluggishly and had to come from 15-40 down in his opening service game before Alcaraz broke to go 2-1 ahead and hold for 3-1.
But the Italian managed to stay in the match as Alcaraz failed to dominate his service games, taking a 4-3 lead to put the pressure on his 22-year-old opponent, who had won 10 of their 16 previous encounters.
Another shaky service game from the Spaniard gave Sinner another break point, and from there he made no mistake, quickly wrapping up his 27th ATP Tour victory.
