Only two men have ever beaten Nadal at Roland Garros: Novak Djokovic produced a masterful display to beat the Spaniard in the 2015 quarter-finals but the first one to do so was Soderling himself in 2009.
And the now-retired Swede believes that aggression is the key to getting past the 10-time French Open champion.
“To beat Rafa on clay, especially in best of five sets you have to be aggressive and dictate the points,” Soderling told the Telegraph.
“That’s how I played naturally so it was maybe a bit easier for me.
Robin Soderling shocked Rafael Nadal at Roland Garros in 2009
“But I also tried to be a bit more aggressive than normal and also take a few more risks, and that day it really worked.”
Soderling’s fourth-round win over Nadal was one of tennis’ greatest shocks, with the No 23 seed listed as a 45/1 underdog ahead of the match.
So it was not without reason that even within tennis, few had given the 24-year-old a chance of winning.
“I remember I beat [David] Ferrer in the third round and the first question the journalist asked me was ‘do you think Rafa will win the French Open again this year?’,” Soderling added.
“At that moment I realised no-one believed I could win. At least I had to otherwise there was no point going on court.
“So I told myself I have a chance, I just have to focus on my game. When I got on court I felt really confident, really good but I also felt like there was no pressure.
“No-one expected to me to win so I tried to see it as there’s only an upside.”
Soderling continued his good form but fell at the last hurdle, losing to Roger Federer in his first ever Grand Slam finale.
He would return 12 months later, where he was again beaten, but that would prove to be the peak of his career as a chronic bout of glandular fever forced him to retire at the age of 26.
And Soderling is concerned that those still playing the game will not be able to repeat his feat of beating Nadal in Paris because they do not share his positive mental attitude when it comes to playing against him.
“I get the feeling even guys in the top five don’t really believe,” Soderling said.
“They’re there to see what happens.
“Their focus is just to go off the court with their head high – you can see it even in the warm-up.
“It means the big guys win many matches before they have even started.
“You have to unsettle these guys and stand up for yourself.
“Show your opponent that you believe in yourself and you’re there to win.”