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, Rafa 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.
Djokovic, who will next take on either Italian Andreas Seppi or the sixth seeded Tsonga of France, ended the one hour 55 minute contest with a scorching service return.
Murray produced a dazzling display as he demolished former world number one Roddick in just 61 minutes.
Briton Murray, who has never made it past the last eight in the Parisian indoor tournament, will next face the fifth seeded Berdych, a Paris Masters champion in 2005.
"I started the match well, which against him is always important, because he plays his best when he's ahead. He's able to put pressure on you and can kind of dominate the match with his serve," Murray told a press conference.
"But because I broke him earlier, I was able to dictate a lot of what happened out there. Played very well. Very few hiccups. I played very smart."
Roddick, the 13th seed, looked helpless throughout as world number three Murray sent him scurrying left and right with his sharp forehand.
Roddick crushed his racket in frustration when he conceded his fourth break against a focused Murray, who gave up only 10 points on serve.
The Scot, who is on a 17-match winning streak after a hat-trick of titles during the Asian swing, ended his opponent's ordeal with an ace.