ATP players aged 35 or over have proved that age is just a number as four men, Novak Djokovic, Adrian Mannarino, Stan Wawrinka, and Gael Monfils all reach the Round of 16 at the Cincinnati Open.

The four players are aged between 35 and 38 and have all had successful runs at the Western & Southern Open in Ohio so far. The youngest is world No. 27 Mannarino (35), who defeated compatriot Richard Gasquet and twelfth seed Felix Auger-Aliassime in straight sets to reach the third round.

The oldest is Wawrinka (38). The Swiss player emerged victorious against Brandon Nakashima in the Round of 64 before defeating tenth seed Frances Tiafoe 6-3, 6-4 in the second round. Wawrinka will face Max Purcell in his Round of 16 match, while Adrian Mannarino will play against Mackenzie McDonald.

Meanwhile, 36-year-olds Djokovic and Monfils are set to face each other in the third round. As the second seed, 23-time Grand Slam champion Djokovic received a bye in the first round and won his first set against Alejandro Davidovich Fokina in the Round of 32 before the Spaniard retired from the match with a back injury.

His opponent Monfils defeated thirteenth seed Cameron Norrie in the Round of 64 and then proceeded to win against Canadian Open finalist Alex de Minaur in straight sets 7-5, 6-4.

These players' progression means that there are more 35+ year-olds left in the tournament than those aged under 25.

Only three players aged under 25 are left in the ATP 1000 tournament. These are world No. 1 Carlos Alcaraz, who is 20 years old, as well as 24-year-olds Emil Ruusuvuori and Alexei Popyrin.

Other top-ranked players aged under 25 such as 20-year-old Holger Rune, 21-year-old Jannik Sinner, and 24-year-old Casper Ruud were all eliminated in their opening matches.

Alcaraz will go on to face fourteenth seed Tommy Paul in his next match, the same player who defeated the top seed at the Canadian Open last week. Meanwhile, Ruusuvuori and Popyrin are playing against each other in the Round of 16.