Novak Djokovic of Serbia competes during the men's singles quarterfinal match between Novak Djokovic of Serbia and Stefanos Tsitsipas of Greece at 2019 ATP Shanghai Masters tennis tournament in Shanghai, east China, on Oct. 11, 2019. (Xinhua/Ding Ting)

SHANGHAI, Oct. 11 (Xinhua) -- Sixth-seeded Stefanos Tsitsipas of Greece recorded his first win over current world No. 1 at the ATP Shanghai Masters here on Friday as he beat the defending champion Novak Djokovic 3-6, 7-5, 6-3 to reach the semifinals.

The 21-year-old also secured his debut at the ATP Finals in London next month after this biggest win of his career.

Tsitsipas will play third seed Daniil Medvedev of Russia in the semifinals after the 23-year-old saw off Italy's Fabio Fognini, the No. 10 seed, 6-3, 7-6 (4) in 86 minutes. Medvedev now has a Tour-leading 57 wins this season and produced a 27-3 match record since July.

Djokovic, who won the Japan Open last week, has never failed to make the semifinals stage in Shanghai and has won the title four times, in 2012, 2013, 2015 and 2018. But this time, his semifinals streak was ended by Tsitsipas.

"He had the high-quality tennis and he played very well after his serve," the 32-year-old Serbia said of the world No. 7 Tsitsipas. "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."

Tsitsipas overcame a slow start in the match, losing the opening three games in seven minutes, only to find his powerful serve in the second set when he improved his first service winning rate to 95 percent.

In the decider, the Greek broke at the third breakpoint in the fourth game to go up by 3-1, before finally sealed the victory 6-3.

Swiss great Roger Federer, the champion in Shanghai in 2014 and 2017, will face Germany's Alexander Zverev later on Friday while fourth seed Dominic Thiem of Austria to play Italy's Matteo Berrettini.