Alcaraz, who became the youngest No. 1 in ATP history after winning the US Open, and Nadal, who completed a spectacular first half of the season where he won, among other tournaments, the Australian Open and Roland Garros, are now leading the Race to Turin, where the ATP Finals are held this year.
This milestone is so unusual that you have to go back to August 7th 2000 to find the last occasion on which two compatriots led the world tennis rankings. Back then it was American legends Andre Agassi and Pete Sampras who topped the rankings. Just goes to show how difficult it is for this to happen.
Despite the good news for the Spanish fans, it will not be easy for this situation to continue due to Nadal's abdominal injury, which will presumably prevent him from playing too many tournaments in the near future.