Rafael Nadal will have one final battle with Novak Djokovic when they meet in the Six Kings Slam exhibition event.

The Spaniard is retiring after next month’s Davis Cup finals in Malaga, bringing the curtain down on an incredible career.

His rivalry with Djokovic has been one of the mainstays of the sport for the last 15 years and there will be one final meeting in Saudi Arabia as the pair will face off in the third-place match on Saturday.

Nadal, playing his first match since the Olympics, was beaten 6-3 6-3 by compatriot Carlos Alcaraz in the semi-final in Riyadh.

Djokovic, a runner-up in Shanghai last week, lost 6-2 6-7 (7-0) 6-4 to Jannik Sinner in the other semi.

It will be fitting that the pair get one more meeting, given their enduring battles over the years, with the pair meeting 60 times at ATP Tour and grand slam level.

“I feel very well supported and loved all around the world,” Nadal said on court after his loss to Alcaraz.

“I am really very fortunate I have had a long and successful career.

“I am probably going to practice on Friday, I am trying my best every single day to be better and better, but I have Davis Cup in front in a month and every day is an opportunity to be better for that.”

Sinner and Alcaraz will continue their burgeoning rivalry in the final on Saturday, with the winner taking home a $US4.5million ($A8.7 million) prize.