Jannik Sinner has now won back-to-back ATP Finals titles without dropping a set

Jannik Sinner has successfully defended his title at the ATP Finals, completing the mission with a 7-6 (4), 7-5 championship victory over Carlos Alcaraz on Sunday.

And with that, he joins a very exclusive list—he's the first player this century, and just the second player ever, to win back-to-back ATP Finals titles without dropping a set.

The only other player to do it was Ivan Lendl, who did it in 1985 (when the event was a 16-player elimination draw with four rounds) and 1986 (when it switched back to the current format of three round-robin matches, then the semifinals and final).

The first edition of the ATP Finals was held in 1970.

PLAYERS TO WIN ATP FINALS WITHOUT DROPPING A SET (since 1970):

Alcaraz nearly ended this stat—the Spaniard held a set point in the first set, with Sinner serving at 5-6, ad-out. But the Italian saved it, held, won the tie-break and then battled back from an early break down in the second set to win in straight sets.

Sinner has now won 20 sets in a row at the ATP Finals, the second-longest set streak in tournament history after Lendl's 24 in a row between 1985 and 1987. Lendl still won his third straight year-end championship title in 1987, he just dropped a set to Boris Becker in the round robin along the way.

Last year, Sinner was never even pushed past 6-4 in any set in Turin. This year, it happened several times—his 7-5, 6-1 and 6-3, 7-6 (3) wins over Felix Auger-Aliassime and Ben Shelton in the round-robin stage, his 7-5, 6-2 victory over Alex de Minaur in the semifinals, then the aforementoned final scoreline.