Stavanger | Reigning world champion D Gukesh finally got his revenge on Magnus Carlsen as he pounced on a blunder by the world no.1 to defeat him for the first time in a classical game in Round 6 of Norway Chess here.

The win on Sunday propelled 19-year-old Gukesh to third position with 8.5 points and he is just one point shy of joint leaders Carlsen and American Grandmaster Fabiano Caruana.

Arjun Erigaisi, following an Armageddon tie-break win against China's Wei Yi, is tied fourth with Hikaru Nakamura on 7.5 points in a tournament where virtually all the six players have a chance of winning the prestigious title.

Five-time world champion Carlsen seemed to have the upper hand almost throughout the four-hour-long contest but a critical mistake in time trouble allowed Gukesh to turn the tables on the Norwegian and secure a remarkable win.

Carlsen realised his mistake but by then it was too late. The Norwegian star vented his frustration by banging on the table, which threw the chess pieces in disarray.

Disbelief and frustration writ large on his face as he shook hands with Gukesh before placing all the pieces on the board and walking away patting the winner on the back.

The magnitude of the achievement saw Gukesh close his eyes for a moment and then soak in the feeling of fulfilment. The victory had come after a crushing Round 1 loss to the Norwegian world No.1, which had cast a shadow on whether Gukesh would be able to overcome Carlsen's challenge in the reverse game. Carlsen, playing with black pieces, had earlier outplayed Gukesh with near-perfect precision. But the Indian kept prolonging the game by finding the right moves to survive.

"There wasn't much I could do. It was just clearly lost… luckily he (Carlsen) got into a time scramble." Gukesh even told the broadcasters after the match that, "99 out of 100 times I would lose… just a lucky day." Carlsen dropped his knight, and Gukesh pounced on his opponent's error to go for the kill.

“First Classical win over Magnus, not the way I expected (or) wanted it to be but I will take it. I was just trying to make moves (today) which kind of were tricky for him and, luckily, he got into a time scramble.

"One thing I learned from this tournament was time scrambles can go out of control,” said Gukesh.

On his loss in Round 1 despite being in an advantageous position, Gukesh said, “I don't know, I'm still kind of shaken from that game. I don't know what happened, basically.

There wasn't much I could do; it was clearly lost. Gukesh's Polish coach Grzegorz Gajewski said the win was a huge confidence booster for the world champion.

“It's going to give him a bump of confidence. Because once you've done it, you know you can do it again. And that's the plan,” said Gajewski.

“After the first game (which Gukesh lost to Carlsen), we saw that the main problem was time management, and because of the time trouble, he managed to lose the position that he should not have lost.

"So, we decided that we had to correct this time management, and already in the game with Hikaru (Nakamura), we could witness this improvement and progress," he added.

The tournament saw another intense day in the women's section with R Vaishali getting the better of Koneru Humpy in the Armageddon tie-break.

Results (Round 6): (Open) D Gukesh (Ind – 8.5) bt Magnus Carlsen (Nor – 9.5); Arjun Erigaisi (Ind – 7.5) bt Wei Yi (Chn – 6.5) in Armageddon tie-break; Fabiano Caruana (USA – 9.5) bt Hikaru Nakamura (USA – 7.5) in Armageddon tie-break. (Women) R Vaishali (Ind – 8) bt Koneru Humpy (Ind – 9.5) in Armageddon tie-break; Ju Wenjun (Chn – 8.5) bt Lei Tingjie (Chn – 6) in Armageddon tie-break; Anna Myzychuk (Ukr – 9.5) bt Sara Khadem (Esp – 6) in Armageddon tie-break.