Rafael Nadal's 2017 French Open success was the ultimate performance at Roland Garros, according to Bjorn Borg, who expects the Spaniard and Roger Federer to challenge at Wimbledon next month.
Nadal did not drop a set en route to winning his 10th title at the clay-court slam in Paris, which represented a 15th career major.
Stan Wawrinka was no match for the 31-year-old in the decider on Court Philippe Chatrier on Sunday, losing 6-2 6-3 6-1.
Borg knows exactly what it takes to triumph at the French Open, having lifted the Coupe des Mousquetaires six times between 1974 and 1981.
"Just the fact that Rafa can play like this is absolutely incredible," Borg told Sportbladet.
"No one has ever performed better in Paris, and his opponent [Wawrinka] is not a bad player.
"No one believed he would be able to make a comeback. But what a comeback he did.
"Winning this way after being injured on and off for some years, it is amazing.
"You can't play more perfect tennis. It would be impossible. I am so impressed by Nadal.
"He is 31 years old and he has still improved his backhand, performing better than in years.
"I'm aware of how hard he has been practicing, working that backhand seven, eight hours a day.
"He has no weaknesses and to him every ball is a match point. That's what I like about Nadal.
"Whoever plays against him is aware Nadal will always give it 110 per cent and never, ever give the ball away."
Having won an unexpected Australian Open title at the age of 35 in January, Federer sat out the French Open to focus on his preparation for the grass court season.
The Swiss and Nadal, who lost to Federer in the decider at Melbourne Park, are now likely to be among the favourites for Wimbledon, nine years on from their thrilling meeting in the 2008 final at the All England Club.
"Yeah just imagine, these 'old men' are back! They will be really dangerous contenders at Wimbledon," Borg said.
"They want to win the titles and raise those cups. Being a tennis player there is nothing better or more wonderful.
"Not many people get the opportunity to lift those cups, but those who do are very proud, that I can promise."