Novak beat Benoit Paire 6-3, 6-3 to clinch the win after Filip Krajinovic beat Jo-Wilfried Tsonga 7-5, 7-6. Viktor Troicki/Janko Tipsarevic face Pierre-Hugues Herbert/Nicolas Mahut in the remaining doubles dead rubber.
Third seed Roger Federer defeated no.2 seed Novak 6-4, 6-3 to reach the last four at the Nitto ATP Finals. The Serb, who has won the season finale title five times, will finish the year as world no.2.
The field is set for the inaugural ATP Cup, to be held from 3-12 January, 2020, in Brisbane, Perth and Sydney. Top seed Serbia, led by Novak Djokovic, will play at the Pat Rafter Arena in Brisbane in Group A with France, South Africa and Chile.
The Austrian rallied to beat Novak 6-7 (5), 6-3, 7-6 (5), and made his first Nitto ATP Finals semis. Djokovic will face no.3 seed and six-time titlist Roger Federer (SUI) on Thursday, for a spot in the last four.