Chess king Carlsen has one-word response after beating Russian rival in longest-ever epic (VIDEO)

Reigning world chess champion Magnus Carlsen has issued a one-word response after finally breaking the deadlock in his title showdown with Ian Nepomniachtchi.

Beating the Russian in the sixth game of 14 following five successive draws, the Norwegian took to social media.

"YES," he wrote past 1am in Dubai, where the spectacle is being held. 

The pair's latest encounter was described as a "grueling back-and-forth marathon," and broke records for being the longest game in 135 years of world championship matchplay history. 

It took in 136 moves and 7 hours and 45 minutes, which surpassed the 124 moves executed in a title match between Nepo's compatriots Anatoly Karpov and Viktor Korchnoi in 1978.

Both players missed out on winning opportunities under the extreme pressure of the clock, but Nepo felt that "Magnus managed to capitalize on the very few chances he got".

"It shouldn’t be easy in a world championship match," Carlsen said himself.

"You have to try for every chance, no matter how small it is. And part of it was by design at some point.

"I thought I should make the game as long as possible so that we would both be as tired as possible when the critical moment came. That turned out to be a good strategy," he concluded.

Going into games scheduled for Saturday and Sunday prior to a rest day on Monday, Carlsen holds a lead of 3.5 points to 2.5 in the best-of-14 series.

His breakthrough at long last was the first decisive result that a world title match has seen at the classical stage for over five years, with 2021's five consecutive draws extending a record run of 19.

These included Carlsen’s last two games against Sergey Karjakin in 2016 as well as all 12 he played against Fabiano Caruana in 2018.