Elimination for Rafael Nadal means Carlos Alcaraz is guaranteed to end the year as world number one
Rafael Nadal's chances of progressing to the knockout stages of the ATP Finals are over after results went against him in Turin on Tuesday night. The early exit for the Spaniard also means that compatriot Carlos Alcaraz is guaranteed to become the youngest player ever to finish the year as world number one.
Nadal has lost both his matches thus far in the round-robin stage of the season-ending tournament in Italy, suffering straight-sets defeats to Taylor Fritz and Felix Auger-Aliassime.
Nadal's hopes of reaching the semifinals could only be kept alive if Casper Ruud lost in straight sets against Fritz on Tuesday, although the Norwegian won his contest against his American rival, 6-3 4-6 7-6 (8-6).
Ruud has won both his matches in Turin after defeating Auger-Aliassime on Sunday, and next plays Nadal on Thursday.
The match will be a dead rubber for the 22-time Grand Slam winner, while Ruud is already assured of a semifinal place.
Nadal's pair of defeats in Turin mean that he has lost four ATP Tour matches in a row for the first time since 2009, while an ATP Finals title continues to elude the 36-year-old despite his glittering career.
In terms of this year's ATP standings, world number two Nadal needed to win the season finale in Italy to overtake Alcaraz as the year-end world leader.
Alcaraz, 19, is now guaranteed to finish the year in top spot - making him the youngest man to do so since the ATP ratings were introduced in 1973.
Alcaraz had been due to play the ATP Finals but was forced to withdraw with injury earlier in November.
Elsewhere in Turin, 21-time Grand Slam champion Novak Djokovic - a five-time ATP Finals winner - plays Russia's Andrey Rublev on Wednesday.
The pair both won their opening round-robin matches against Stefanos Tsitsipas and Daniil Medvedev respectively.
Tsitsipas and Medvedev meet later in the day as they seek to avoid early elimination from a tournament they have both won in previous years.