Ding exploited a big mistake from his Russian rival, playing under a neutral flag, to secure victory at the St. Regis Astana Hotel in the Kazakh capital.

The match looked like heading for a second successive draw before Nepomniachtchi made the crucial blunder when he made a move that left him in a losing position.

There was no escape as Nepomniachtchi resigned on move 47 after almost four hours of play to hand the 30-year-old Ding victory.

"Of course, I am very happy to win the game," said Ding.

"I am pleased with the quality of my play.

"It was a very hard game, and I managed to keep things under control.

"For me, it is the most important win so far, since the World Championship is totally different than, for example, the Candidates."

"For me, it is the most important win so far, since the World Championship is totally different than, for example, the Candidates."

Nepomniachtchi added: "It was a very intense game.

"I think I misjudged the position and thought it was quite nice for black.

"Still, it was more or less playable, until I just lost my focus.

"I will surely discuss it with my team tonight.

"It is a long match, and we are just at the beginning."

The players will enjoy a rest day tomorrow before resuming for game five on Saturday (April 15).