Humble Swiss Stan Wawrinka says it's "completely crazy" to have won the French Open and refuses to believe he belongs in the conversation alongside tennis' so-called Big Four.

But that's exactly where he is after accessing one of the most exclusive clubs in the game with his stirring 4-6 6-4 6-3 6-4 victory over world No 1 Novak Djokovic in a pulsating final at Roland Garros in Paris.

In denying Djokovic his own place among the sport's immortals, Wawrinka follows superstar countryman Roger Federer, as well as Djokovic, Rafael Nadal and Andy Murray as only the fifth man in the past decade to snare multiple majors.

"It is amazing, for sure," Wawrinka said after becoming the oldest French Open champion in a quarter of a century and proving his 2014 Australian Open triumph was anything but a fluke.

"I still have a problem to really realise that I won the French Open because it's always the same after winning a big title; you are a little bit lost in your mind.

"Honestly, I didn't think that I could be in a position to win another grand slam tournament."

The 30-year-old says it's impossible to rank his latest success with his success in Melbourne, where he also upset Djokovic before beating Nadal in the final.

"I don't try to compare at all," Wawrinka said.

"For me, this one is really special for sure, playing Novak here in final, the No 1 player.

"He won almost everything since the beginning of the year."

Australian coach Darren Cahill, who guided Andre Agassi and Lleyton Hewitt to the top of the rankings, believes Wawrinka deserves Hall of Famer status after winning two slams in the golden era of Federer, Nadal, Djokovic and Murray.

But despite rising to No 4 in the world and Nadal slumping to 10th - the Spaniard's lowest ranking in a decade - Wawrinka modestly dismisses talk of the "Big Four" expanding to a "Big Five".

"I'm not as good as they are," he said.

"But I'm quite good enough to win two grand slam tournaments.

"I can beat them in major tournaments, in a semi-final, in a final.

"But once again, the 'Big Four' will always be the 'Big Four'.

"I don't want to be in comparison with them. I want to make progress and strides. I want to beat them. That's all. It is as simple as that."

But despite entering Sunday's final as a heavy underdog Wawrinka, the 2003 junior champion who lost in the first round last year at Roland Garros, proved too strong for Djokovic.

The eighth seed used the same deadly one-handed backhand, surgical serve and steely resolve that devastated Djokovic and Nadal in Melbourne 18 months ago - and Federer in the quarter-finals last week - to once again destroy the Serb's grand slam dreams.

The free-hitting Swiss crunched 60 winners in all, double Djokovic's 30, and fittingly nailed a signature backhand down-the-line winner on his second match point to reign supreme after three hours and 12 minutes. -AAP