Czech Tomas Berdych booked his place for the ATP World Tour Finals with a 7-5, 6-4 win over Serb Janko Tipsarevic. Berdych's win meant Jo-Wilfried Tsonga and Mardy Fish also qualified for the eight-man field in the Nov 20-27 event at the O2 in London.
The line-up for the season-ending tournament is now complete as Djokovic, Rafael Nadal, Andy Murray, Roger Federer and David Ferrer had already secured their berths.
While Murray breezed past a clueless Andy Roddick 6-2, 6-2, Djokovic made heavy weather of Troicki, with whom he won the Davis Cup last year.
Djokovic's phenomenal performance in winning three grand slam and five Masters titles this season seemed to be a distant memory as he found himself trailing following an unusual string of unforced errors.
Troicki, however, failed to seize his chance in the second set as Djokovic saved seven break points, converting his only two opportunities to level the tie.
Djokovic, who pocketed a $1.6 million bonus for just turning up at Bercy by virtue of an ATP rule designed to entice top players to show up at top events, stepped up a gear in the final set while a demoralised Troicki collapsed and dropped serve three times.
