Novak Djokovic said the long awaited "shift of generations" has finally come to men's tennis after the world No. 1 lost to 20-year-old Dane Holger Rune in the Italian Open quarterfinals on Wednesday.

The "Big Three" of Djokovic, Rafael Nadal and Roger Federer have dominated the ATP Tour for nearly two decades, but age and injury have been catching up with them in recent years.

Djokovic's 6-2, 4-6, 6-2 loss to Rune means that for the first time in 19 years, neither the Serb nor the injured Nadal will play in the Rome final.