The top seed completed an impressive 6-2, 6-2, 6-3 win over rising Bulgarian star Grigor Dimitrov before tournament organisers announced that he would be unavailable for the customary post-match interview as a sign of respect for his fellow Serb. Gencic noticed Djokovic’s talent when he was six years old and with the agreement of his parents trained him for five years before he left for further coaching in Germany.
“When I met him I knew immediately that he was different. I told his father that he was an exceptional talent and that one day he will be a big champion,” she said in an interview.
After winning Wimbledon in 2011, Djokovic visited her in Belgrade to celebrate the win with his former coach.
Gencic, a retired handball and tennis player, has also trained other former top players Monika Seles and Goran Ivanisevic.
Djokovic, who is seeking in Paris to become just the eighth man to win all four Grand Slam titles, was never troubled by Dimitrov, who beat him in the second round of the Madrid Masters last month.
It was the 500th win of his professional career which started in 2003, but there were concerns late on in the match against Dimitrov when he needed treatment for a pain in his right arm.
Djokovic will go up against Phillip Kohlschreiber of Germany for a place in the quarter-finals today.