Stefanos Tsitsipas will play Dominic Thiem for the title at the ATP Finals on Sunday after beating six-time champion Roger Federer in London.
The Greek, Stefanos Tsitsipas won 6-3 6-4. Swiss Federer, 38, who was aiming for his seventh title but was defeated by the determined Tsitsipas. Later, Austrian fifth seed Thiem saw off defending champion Alexander Zverev 7-5 6-3 at the 02 Arena.
Thiem and Tsitsipas will be competing in the first final at the season-ending tournament and aiming for the biggest title of their careers. Tsitsipas is the youngest finalist since Juan Martin del Potro in 2009, while it will be just the third final since 2002 not to include Federer, Novak Djokovic or Rafael Nadal.