Andy Murray was back on a clay court for the first time since his hip problems flared up in 2017 but he was no match for old foe Stan Wawrinka, losing 6-1 6-3 6-2 in the first round of the French Open.
It is Murray's joint worst defeat at a Grand Slam along with a semi-final loss to Rafael Nadal in Paris in 2014.
He said: "I need to have a long, hard think about it. 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."
Murray was taking on Wawrinka in their first meeting at Roland Garros since their semi-final in 2017 that proved the final straw for his hip.
It also left Wawrinka needing knee surgery that might have ended his career, so it is no surprise that the two men have a certain affinity.
Wild card Murray was looking to at least be competitive, but he was unable to trouble the 2015 French Open champion who looked as if he could hit the ball through a brick wall, let alone a clay court, with the slow conditions very much to his liking.
It was so cold that Murray was wearing leggings under his shorts and there was sluggishness about his movement and particularly his serve.
Murray held serve on the opening game of the match but then Wawrinka reeled off 18 out of 22 points to seal it 6-1.
There were a few more positive signs in the second set but Murray, who was unusually reserved, was still left motionless far too often as Wawrinka bulldozed the ball into the corners.
A break of serve right at the start of the third set brought the finish line closer, and Murray was unable to take any of his first three break points when he had Wawrinka at 0-40 in the next game.
The Scot just looked so underpowered compared to his opponent and he was left rooted to the spot once more as Wawrinka drilled a backhand winner into the corner to break for 5-2 before serving out the victory with an ace.
And Wawrinka brushed his opponent aside in the third set with two more breaks of serve to close out the contest in one hour and 37 minutes.
The 33-year-old 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 in terms of 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 mean, I'm 33 now and I was ranked number one in the world, so it's difficult with all the issues that I have had.
"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."
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