At 36 years old, Roger Federer will become the oldest tennis player to reach No. 1 when the new ATP World Tour rankings are released Monday.
He accrued the points the needed with a three-set victory Friday over Robin Haase at the Rotterdam Open in the Netherlands.
BBC Sport confirmed Federer is set to overtake longtime friendly rival Rafael Nadal, who's been sidelined with a thigh injury.
ESPN Stats and Info noted that the Switzerland native will also establish the new mark for longest gap between stints in the top spot and add to his record for most total weeks at No. 1:
It's the latest accomplishment as part of his remarkable resurgence.
Federer won a single Grand Slam title between the 2010 French Open and the 2016 U.S. Open (Wimbledon in 2012). He's proceeded to win three of the last five despite not even participating in last year's French Open to rest.
After winning the Australian Open in January for his 20th major singles title, the fan favorite didn't tip his hand about how long he plans to play, but he noted he can't overextend himself.
"I've just got to keep a good schedule, stay hungry, then maybe good things can happen. Then I don't think age is an issue, per se. It's just a number," he told reporters. "But I need to be very careful in my planning, really decide beforehand what are my goals, what are my priorities. I think that's what's going to dictate how successful I will be."
Federer will face either Andreas Seppi or Daniil Medvedev in the Rotterdam Open semifinals Saturday.