PARIS: Novak Djokovic completed his career Golden Slam as the 37-year-old Serb fought off Spain's Carlos Alcaraz in a magnificent Olympic men's singles final battle at Roland Garros on Sunday.

After heartbreak in Beijing, London, Rio de Janeiro and Tokyo, Djokovic simply would not be denied the one title that had eluded him for so long, winning 7-6(3) 7-6(2) in front of an enthralled crowd on Court Philippe Chatrier.

Top seed Djokovic delivered one of the finest performances of his career to deny Alcaraz and become only the fifth player to win all four singles Grand Slams and the Olympic title.

Neither player took a backward step in a ferocious contest in which the first set alone lasted one hour 33 minutes as they wrestled for control in a series of spellbinding games.

Alcaraz cracked first in the tiebreak and when another tiebreak was required to decide the second set, again Djokovic again found another gear, sealing victory with a stunning forehand winner down the line.

Djokovic roared to the sky and after consoling Alcaraz at the net he then fell to his knees and sobbed in the centre of the court before climbing into the crowd to be swamped by his family, friends and team.

While Djokovic, the oldest player to win the Olympic singles title since the sport returned to the Games in 1988, cried tears of joy, the 21-year-old Alcaraz was inconsolable after falling short of adding the gold medal to this year's French Open and Wimbledon crowns.

Djokovic, had lost three times in Olympic singles semi-finals and knew arriving in Paris this was his last realistic chance to fill the last remaining space in a trophy cabinet that contains a men's record 24 Grand Slam titles.

And how he earned it - overturning his crushing loss to Alcaraz in last month's Wimbledon final to become the first man to win the Olympic singles without dropping a set.

"It was an incredible fight and I had to play my best tennis," an emotional Djokovic told Eurosport before the medals ceremony as Serbian fans celebrated in the stands.

"It was fair that the two sets finished in tiebreaks. I put my heart, my soul, everything to win gold.

"I did it for my country first, for Serbia."

Djokovic joins an elite club of Andre Agassi, Rafa Nadal, Serena Williams and Steffi Graf in winning all four Grand Slams and the Olympic title in their careers.