French Open 2014: Novak Djokovic drops set against Marin Cilic on way through at Roland Garros

The second seed remains on course in Paris

Serbia's Novak Djokovic (R) is congratulated by Croatia's Marin Cilic at the end of their French tennis Open third round match at the Roland Garros (GETTY IMAGES)

Second-seed Novak Djokovic was given a work-out before earning his ninth straight victory over Marin Cilic to move into the fourth round of the French Open on Friday.

Djokovic was not at his best as he battled to a 6-3 6-2 6-7 (2-7) 6-4 victory to preserve his unbeaten record against Cilic.

The Croatian started strongly, moving into a 3-1 lead before Djokovic won out to take the opening set.

Even then, Djokovic was guilty of unforced errors and allowed Cilic to break back in the fourth set after taking a 4-2 lead.

The match took more than three hours to complete, but Djokovic eventually emerged with a win which will see him face either world number 14 Jo-Wilfried Tsonga or 22nd seed Jerzy Janowicz in the next round.

PA