World number one Novak Djokovic was knocked out of the Shanghai Masters quarter-finals by Greek’s sixth seed Stefanos Tsitsipas.
The 21-year-old sixth seed, came from a set down – having lost the opening three games in seven minutes – to beat the defending champion 3-6 7-5 6-3.
It was Tsitsipas’ first win against the current world number one.
Friday’s win confirms Tsitsipas’ debut at next month’s ATP Finals in London.
Djokovic – who won the Japan Open last week – has never previously failed to make the semi-finals in Shanghai.
He now trails Rafael Nadal by 1,280 points in the battle for year-end world number one.
Tsitsipas will now play Daniil Medvedev in the semi-finals after the Russian defeated Fabio Fognini 6-3 7-6 (7-4).
Reacting to his shock defeat, Djokovic said:”He had the high-quality tennis and he played very well after his serve.
“He was backing up his serve with really good and aggressive first shots in the rally.
“I didn’t make him defend enough. I just gave him enough time to really dictate the play from back of the court and he deserved to win.”