Roger Federer celebrates tonight after reaching the Paris Masters semi-finals ©Getty Images

Roger Federer defeated Kei Nishikori at the Association of Tennis Professionals (ATP) Paris Masters event tonight to secure a semi-final meeting with the newly established world number one, Novak Djokovic.

Federer’s late night 6-4, 6-4 win over his Japanese opponent completed the quarter-final schedule at the Palais Omnisports at Bercy.

It also assured him of a meeting with the Serbian who returned automatically to the peak of the game when Rafael Nadal withdrew from this tournament on Wednesday.

 Djokovic came from a set down to beat Croatian rival Marin Cilic 4-6, 6-4, 6-4 and extend his current winning run to 21 matches.

Dominic Thiem of Austria salutes his quarter-final victory over Paris Masters defending champion Jack Sock of the United States ©Getty Images
Dominic Thiem of Austria salutes his quarter-final victory over Paris Masters defending champion Jack Sock of the United States ©Getty Images

Earlier in the day, sixth-seeded Dominic Thiem beat defending champion Jack Sock of the United States 4-6, 6-4, 6-4

The 25-year-old Austrian, whose victory meant that he would qualify for the season-ending ATP Finals in London if Federer defeated Nishikori in the last match of the day – now meets Karen Kachanov in the Paris semi-finals.

The Russian earned a swift 6-1, 6-2 victory over Germany’s Alexander Zverev in the opening match of the day.