What was billed as an opening-day classic between two old warriors turned into a damp squib as Stan Wawrinka crushed Andy Murray 6-1 6-3 6-2 at the French Open on Sunday.

The last time they met on Court Philippe Chatrier, in the 2017 semi-final, Wawrinka came through a five-set slugfest but this time it proved a painfully one-sided affair as Murray suffered his equal worst Grand Slam beating.

When the opening three games on a near-empty showcourt took around 20 minutes, another battle royal looked possible between the players who have both won three Grand Slam titles.

But as 16th seed Wawrinka, champion in Paris in 2015, raised his game, Murray, who wore black leggings on a chilly evening, capitulated alarmingly with his trademark battling qualities conspicuous by their absence.

"I need to have a long hard think about it. It's not the sort of match I would just brush aside and not think about it," Murray, whose previous worst loss was a 6-3 6-2 6-1 hammering at the hands of Rafa Nadal at the 2014 French Open, told reporters.

"I need to understand why the performance was like that."

Murray's defeat by Wawrinka in 2017 was the final straw for a hip that has since required two surgeries, the second of which has left him with a metal joint.

But the 33-year-old returned to singles action last year and actually beat Wawrinka to win the Antwerp title in October – a result that raised hopes he could again challenge at the top.

He was soundly beaten by young Canadian Felix Auger Aliassime in the second round of the U.S. Open though and was hit off court by 35-year-old Wawrinka who has also been forced to come back from knee surgery.

Murray landed only 36 per cent of his first serves which was never going to end well against a player with Wawrinka's brutish groundstrokes.

"That's just not good enough, really, against anyone, and especially someone as good as Stan," he said.

Even his usually sublime touch was off and one dropshot late in the second set failed to even reach the net.

While Murray was a shadow of his former self, Wawrinka sounded a warning that he could be a threat.

It was only his second Tour-level match since the resumption of tennis from the coronavirus shutdown, but he served magnificently and clubbed 42 winners to Murray's 10.

With the conditions likely to remain heavy, Wawrinka will be confident of an extended run.

Japan's Kei Nishikori surrendered two sets 6-1 but still managed to battle past Britain's Dan Evans on Sunday and into the second round of the French Open.

The 30-year-old, playing only his fifth match of the season after a recovery from elbow surgery sidelined him early in the year and then a positive COVID-19 test ruled him out of the US Open, won 1-6 6-1 7-6(3) 1-6 6-4.

"I kind of knew what was the problem in the first set," Nishikori told reporters. "I think I was rushing too much.

"I was a little more patient from the second set. Things started working well for me. It was raining heavy. It was not the usual situation but from the second set, I start playing better. But there were many ups and downs."

Evans, the 32nd seed, looked on course for his first ever French Open win as he romped through the opening set but Nishikori polished off the second set in equally quick time.

Nishikori led 5-2 in the third set only to be dragged into a tiebreaker, which he won, but again lapsed as Evans hit back to take the match into a deciding set.

A topsy-turvy match saw three-time French Open quarter-finalist Nishikori seize control to lead 3-0 but again Evans reeled off the next three games and had a break point in the seventh that he could not convert.

That proved crucial as Nishikori produced a couple of stunning points to break the Evans serve at 4-5 and seal the victory, only his second of the year.

The world number 35, who has now won 24 of his 30 five-set matches in Grand Slam tournaments, will take on Italy's Stefano Travaglia in the second round.

(With input from agencies)