Zverev defeats Alcaraz to reach ATP Finals last four as Spaniard crashes out
World number two Zverev ensured he would advance after taking the first set after more than an hour of battle in northern Italy and then swept through the second for his third victory in as many matches.
Alcaraz, who won Wimbledon and the French Open this season but has struggled for form in Turin, has been eliminated as there is no combination of results between Andrey Rublev and Casper Ruud later in the day that can save him.
Rublev, who has lost his last six Finals matches, can still progress with a straight sets win over Ruud despite having lost his first two matches.
Zverev's qualification from the John Newcombe Group means that three of the four semi-final spots have been filled, with Jannik Sinner and Taylor Fritz through from the Ilie Nastase Group.