Greece's Stefanos Tsitsipas battled back from a set down to defeat top seed Novak Djokovic 3-6 7-5 6-3 in the Shanghai Masters quarter-finals on Friday for his first victory over a reigning world number one.
The 21-year-old came into the match having sealed his place in next month's season-ending ATP Finals and celebrated with his second career win over Djokovic in three meetings.
Tsitsipas has now recorded victories over all of tennis's so called 'Big Three' this year, having beaten Roger Federer at the Australian Open and Rafa Nadal in Madrid.
"He had the high-quality tennis and he played well after his serve. He was backing up his serve with really good, aggressive first shots in the rally," Japan Open winner Djokovic, who came into the match on a seven-match winning streak, told reporters.
"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."