Novak Djokovic during a press conference after his quarter final defeat to Austria's Dominic Thiem. Photo: Benoit Tessier/Reuters

Serbia's press on Thursday lamented the poor performance of national tennis hero Novak Djokovic after he crashed out of the French Open, the latest shock in a year-long slide in form.

Defending champion Djokovic suffered a stunning 7-6 (7/5), 6-3, 6-0 quarter-final defeat to Austria's Dominic Thiem in what was his earliest exit at Roland Garros in seven years.

The 30-year-old Serb hinted that he may step back from the sport to regroup, just 12 months after holding all four Grand Slam titles.

"This has not happened to Novak in the past 12 years," read a headline in Blic newspaper's online edition.

The defeat was Djokovic's first straight-sets loss at a major in four years and his first 6-0 "bagel" at a Slam since the 2005 US Open.

"Djokovic outplayed like never before," read a headline in the Politika daily, which lamented his "inglorious farewell to last year's title".

"What was worst about this failure was not the really negative result... but that Djokovic did not have the slightest chance in the second and third sets, nor did he show any of the quality seen in his best days," commented the newspaper.

The Vecernje Novosti newspaper said the defeat "will cost a lot" as Djokovic may now fall to fourth position in the world rankings.

The former world number one was knocked off top spot in November by Britain's Andy Murray.

Last month he announced he had parted ways with his training team, including long-time coach Marian Vajda, believing that this "shock therapy" could help him return to the top of the game.

He then brought in Andre Agassi as coach.

Djokovic lives in Monaco but remains hugely popular in his native country, where he set up a foundation developing early childhood education projects.