Andy Murray vowed to have "a long, hard think" after suffering the joint worst grand slam defeat of his career to Stan Wawrinka in the first round of the French Open.

Much had been made of the old foes being drawn together again three years after a brutal semi-final at Roland Garros proved the end of Murray's right hip.

The cold and damp conditions were the same but the similarities ended there as 2015 champion Wawrinka took just an hour and 37 minutes to ease to a 6-1 6-3 6-2 victory.

Murray served poorly and was left helpless on the court as his clay-court return proved a chastening experience.

The Scot has only previously won as few games at a slam match in a 2014 semi-final in Paris against Rafael Nadal, but those days feel a long time ago.

Murray did not use his physical struggles or the cold weather as an excuse, saying: " I served under 40 per cent first serves in the court – that's just not good enough, really, against anyone, and especially someone as good as Stan.

"It's not for me the sort of match I would just brush aside and not give any thought to. There is obviously reasons behind a performance like that.

"I think that's the worst defeat maybe of my career in a grand slam. I don't feel like the conditions are an excuse for it. So I'll need to have a long, hard think and try and understand what happened."

Wawrinka may be 35 and having fought back from his own injury troubles, undergoing two knee surgeries while Murray was fighting to preserve his own career. But he is still a proven performer at the grand slams and he quickly set about dismantling the Murray second serve.

It was so cold that Murray was wearing leggings under his shorts and there was sluggishness about the 33-year-old's movement and particularly his serve.

He won just 11 points on serve during the first set as Wawrinka reeled off six games in a row. There were a few more positive signs in the second and third sets but never any real threat of a comeback.

The Scot said ahead of the tournament that he still believes he can win titles, and there is certainly no lack of appetite, with Murray discussing his plans for an immediate switch to indoor hard courts.

He remains confident he can play at a much higher level going forward, saying: "I wouldn't expect to physically be the same as what I was before I had the operation.

"But, in terms of ball striking and my strokes and stuff, there is no reason that I shouldn't be able to do that from a technical perspective.

"There has been matches that I have played since I came back where I hit the ball well. It's going to be difficult for me to play the same level as I did before. I'm 33 now and I was ranked number one in the world.

"But I'll keep going. Let's see what the next few months holds, and I reckon I won't play a match like that between now and the end of the year."

Murray's physical limitations have led many observers to ask whether he should be trying to play a more offensive game, and the Scot admitted he has considered it.

He said: "It's something I have looked at. But it's a difficult one, because the way that I play, if you consider when I play my best tennis or when I played my best tennis, I know what that looks like. It's not going around blasting balls and serving and volleying and stuff.

"To totally change the way you play the game is hard. I need to play better to allow me to play the right way, I think."

Former world number one Mats Wilander, meanwhile, believes Murray should not be accepting wild cards into grand slams that could go to younger players.

The Swede, who is working for Eurosport, said: "I worry about Andy Murray. I keep getting a little bit disappointed. Is it his right to be out there doing that? Why? I did it and I shouldn't have, it was the biggest mistake I did in my career.

"I think Andy Murray needs to stop thinking of himself and start thinking about who he was. It's tough to quit, for sure. I love the fact that he is back and trying. Hopefully he'll figure out why he's doing it."