The Chinese player, playing black, gambled on surprising his opponent by playing the French Defence - something not seen at the World Championship since 1978.

He created a solid position for himself but then, with just 44 seconds on his clock, played a wrong move which meant his position became hopeless.

Nepomniachtchi, playing under a neutral flag, was happy to take the initiative again after playing what he described as one of his "worst games ever" when his errors gave Ding a victory that enabled him to draw level in their gripping International Chess Federation (FIDE) meeting at the St Regis Astana Hotel in Kazakhstan’s capital.

Competition resumed today after a rest day, and Ding appeared to be maintaining his new momentum until his distressing late collapse.

"I told Richard [Rapport, Ding’s second] that I was going to play the French Defence," Ding told FIDE.

"But it was a half-joke, half-serious.

"He took me seriously and told me that I can try this French Defence to surprise my opponent."

The game lasted 37 moves and just under four hours.

It is the third time Nepomniachtchi has taken the lead in this dramatically fluctuating match between two challengers who are contesting the title which Magnus Carlsen, Norway’s five-times winner, announced last July he would not defend on this occasion.

The first 40 moves in each game are subject to a time control of 120 minutes, followed by 60 minutes for the next 20 moves, and then 15 minutes for the remainder of the game with an increment of 30 seconds per move starting from move 61.

The match has reached its halfway point, with 14 matches scheduled, although the first to seven and a half points will win.

Game eight will take place on Thursday after a rest day.

In the event of a tie, the Championship is to be determined in a rapid chess playoff.

The official sponsor, Freedom Holding Corporation, has put €2 million (£1.76 million/$2.2 million) into the prize fund with 60 per cent going to the winner and 40 per cent to the runner-up.