Rafael Nadal says he knows he must improve his level if he is to beat top seed Novak Djokovic and win a record-extending 13th French Open crown.

Djokovic, one of the men to beat Nadal there, has lost only one match in 2020 - when he was defaulted at the US Open.

"I know to play against Novak, I need to play my best," Nadal, 34, said.

If Nadal wins, he will move level with Swiss rival Roger Federer's all-time leading tally of 20 Grand Slam men's singles titles.

Djokovic, who has claimed 17 majors, will narrow the gap on both Federer and Nadal if he wins.

The King of Clay versus the King of 2020

Nadal, bidding to become the first person to win 100 singles matches at Roland Garros, has not dropped a set on his way to the final.

However, he was pushed by Italian teenager Jannik Sinner in the quarter-finals and only faced a seed for the first time when he beat Argentina's Diego Schwartzman in the semi-finals.

Djokovic, 33, has dropped only three sets but appears to be playing at a higher level than his great rival.

The world number one has won all 37 of his completed matches in 2020, with his only loss coming when he was defaulted from that infamous US Open fourth-round match against Carreno Busta last month.

Nadal did not go to New York because of concerns about the coronavirus pandemic and has played only nine matches since March as a result.

"Without playing my best tennis, the situation [against Djokovic] is very difficult," said Nadal, whose only other defeat on the Roland Garros clay was against Sweden's Robin Soderling in 2009.

"I know that is a court that I have been playing well on for such a long time, so that helps.

"But at the same time, he has an amazing record here too, being in the final rounds almost every single time.

"He is one of the toughest opponents possible. But I am here to keep trying my best.

"I know I have to make a step forward. I think I did one in the semi-finals. But for Sunday that is not enough. I need to make another one.

"That's what I'm looking for. I am going to work hard to try to make that happen."

With the tournament pushed back to October because of the coronavirus pandemic, the colder conditions in the Paris autumn are not quite to Nadal's liking as much as the hotter, bouncier surface on which the final is usually played in June.

"I think that could be a better chance for me, obviously the ball not bouncing as high over the shoulder as he likes it usually," said Djokovic, who won his only French Open title in 2016.

"Regardless of the conditions, he's still there, he's Rafa, he's in the finals and we're playing on clay."

One of sport's most enduring rivalries is renewed

Djokovic and Nadal have played against each other more than any other two men and take to the court together for a record-extending 56th time on Sunday.

The pair have produced some of the sport's greatest matches, meeting in:

After his win in the ATP Cup in January, Djokovic leads the head-to-head by 29 wins to 26 for the Spaniard.

Nadal, however, has a superior record in Grand Slams, having won nine of their 15 matches.

Most of them came earlier in Djokovic's career and Nadal has lost the past three meetings at majors - including the 2015 quarter-final at Roland Garros.