Rafael Nadal's record tally of 12 French Open titles will still be talked about "in 200 years", says former British number one Greg Rusedski.
Nadal, 33, is the first player to win a dozen singles titles at the same Grand Slam.
The Spanish second seed beat Austria's Dominic Thiem 6-3 5-7 6-1 6-1 in Sunday's final at Roland-Garros.
"This is the unbreakable record," former US Open finalist Rusedski told Tennis ChitChat.
Nadal's third successive win on the Paris clay moved him clear of Margaret Court's tally of 11 Australian Open titles.
The Spaniard is only the second player to win the same tour singles event a dozen times, with Martina Navratilova having won 12 titles at Chicago between 1978 and 1992.
"Most players don't win 12 titles in their careers, he has won 12 clay-court majors at Roland-Garros," Rusedski said.
"When we're dead, in 200 years from now, people will be talking about Rafael Nadal winning 12 French Opens.
"It is incomprehensible.
"This is the Tour de France of tennis and to do it 12 times is superhuman."
Most men's singles titles at the same Grand Slam in the Open era
12 Rafael Nadal - French Open 2005-2008, 2010-2014, 2017-2019
8 Roger Federer - Wimbledon 2003-07, 2009, 2012, 2017
7 Novak Djokovic- Australian Open 2008, 2011-2013, 2015-16, 2019
7 Pete Sampras- Wimbledon 1993-95, 1997-2000
6 Bjorn Borg- French Open 1974, 1975, 1978-1981
6 Roger Federer- Australian Open 2004, 2006, 2007, 2010, 2017, 2018
By beating 25-year-old Thiem for the second successive year in the final, Nadal increased his tally to 18 major triumphs.
Only long-time rival Roger Federer has won more Grand Slams, sitting two ahead of the Mallorcan in the all-time list of men's singles triumphs.
Serb world number one Novak Djokovic, who was denied the chance to hold all four Slams at the same time by Thiem in the semi-finals, is now three behind Nadal.
Nadal, 37-year-old Federer and 32-year-old Djokovic have won the past 10 Grand Slam titles between them.
Britain's Andy Murray was the last player under 30 to win a Grand Slam men's singles title when he won Wimbledon aged 29 in 2016.
"The last 'next generation' had a lot of war wounds against the likes of Federer, Nadal, Djokovic and Murray, they didn't necessarily believe they could possibly beat these guys," Rusedski, 45, said.
"But I think the new guys - led by Stefanos Tsitsipas, Felix Auger-Aliassime, Denis Shapovalov - this generation may not have the same war wounds.
"And in a couple of years obviously Roger will be nearly 40 and Rafa and Novak will be in their mid-30s - if they are all still playing then.
"To do what they are doing is unheard of.
"It is still those big three and the other guys are trying to knock on the door.
"We want to see one of those younger guys take a Slam."