Novak Djokovic joined Roger Federer, Andy Murray and Rafael Nadal in the semi final of the ATP World Tour Finals with victory over Tomas Berdych in London.
The world number one required just one set to qualify and won his final group match 6-3 7-5.
Federer had already won the group but earlier maintained his 100% record with a 7-5 4-6 6-4 win over Kei Nishikori.
Djokovic will face Rafael Nadal in Saturday’s semi-final, before Federer takes on Andy Murray or Stan Wawrinka.
