Indian teenager Gukesh Dommaraju capped a stunning ascent to the pinnacle of chess by dethroning China’s Ding Liren to become the youngest ever world champion on Thursday in Singapore.

The 18-year-old from Chennai dramatically snatched the decisive victory from a dead-drawn position in the final contest of their best-of-14-games showdown when Ding made one of the worst blunders in the 138-year history of world championship matchplay. The 32-year-old defending champion resigned moments later after a game that lasted 58 moves and just over four hours, sealing Gukesh’s 7½-6½ win in the three-week match and rendering moot the widely expected prospect of tiebreaker matches on Friday afternoon.

In doing so, Gukesh shattered the age record held by Garry Kasparov, who was 22 when he toppled Anatoly Karpov in 1985.

Gukesh admitted he didn’t initially recognize Ding’s rook move (55 Rf2??) as a blunder, saying it took a few seconds to spot that his opponent’s bishop was trapped. He could barely conceal his excitement upon the discovery, while a devastated Ding could only bury his head in his hands.

“When I realized it, it was probably the best moment of my life,” said Gukesh, who brings home the $1.35m (£1.06m) winner’s share of the $2.5m prize fund along with the sport’s most prestigious title.

Ding, playing with the favored white pieces, was slightly better out of the opening but Gukesh was able to unlock his pieces and stabilize in the middlegame. The draw appeared inevitable when material starting coming off the board in bunches starting with move 19.

But a game that appeared bound for a peaceful result suddenly became complicated when Ding sacrificed a pawn in exchange for a simpler position. That left Gukesh with no choice but to fight on and he was more than happy to punish his foe in a grueling endgame under mounting time pressure.

That’s when Ding finally cracked.

“I was totally in shock when I realized I made a blunder,” Ding said. “His facial expression showed that he was very happy and excited and I realized I made a blunder. It took some time to realize it.”

Indian prime minister Narendra Modi was among the first to congratulate Gukesh after he became only the second world champion from India along with Viswanathan Anand, who held the crown from 2007 through 2013.

“Historic and exemplary!” Modi wrote on X. “Congratulations to Gukesh D on his remarkable accomplishment. This is the result of his unparalleled talent, hard work and unwavering determination.”

After Ding resigned, the tears flowed as Gukesh sat at the board overcome by emotion while hundreds of his supporters set off scenes of jubilation in the spectators’ area.

“I probably got so emotional because I did not really expect to win from that position,” Gukesh said. “I was going to press it for as long as it as I could possibly press, but I thought, ‘It’s OK. We are going to play for five, six hours. It’s going to end in a draw, and let’s focus on the tiebreaks.’

“But then suddenly after Rf2, I saw [the game] was actually done. I was already preparing myself to go through that huge tiebreak fight and suddenly it was all over and I had achieved my dream. I’m not someone who shows a lot of emotions, but I think this one can be forgiven.”

Last year Ding became the first men’s world chess champion from China by defeating Russia’s Ian Nepomniachtchi in Kazakhstan, capturing the title abdicated by longtime world No 1 Magnus Carlsen of Norway. But he’d played very sparingly in the 19 months since then amid a well-documented bout with depression, including a nine-month hiatus to prioritize his mental health.

He entered the title match having gone 28 classical games without a win, a dreadful run of form that saw him drop to 23rd in the world rankings and prompted the oddsmakers to install him as roughly a 3-1 longshot in the match. But he sprang a major surprise in Game 1 by winning as black, ending the 304-day winless streak with a riveting opening salvo.

Game 2 was a quiet draw, before Gukesh roared back with a win in Game 3. The fourth, fifth, sixth, seventh, eighth, ninth and 10th games were each draws. Gukesh won on Sunday in Game 11 before Ding struck back in Monday’s Game 12. The 13th game on Wednesday saw Ding hold on in a high-wire draw, leaving the score at 6½-all entering Thursday’s finale at Resorts World Sentosa, an island resort off Singapore’s southern coast.

While Ding had been regarded as the underdog in the match due to his unremarkable form, he would have gone off as a slight favorite if Game 14 was drawn and the match was settled on Friday with a series of tiebreak games with faster time controls.

“Champions always step up to the moment,” the fifth-ranked Gukesh said. “Obviously the past two years he hasn’t been in great shape, but he came here. He was obviously struggling during some of games. He was probably not at his best physically. But he fought in all games. He fought like a true champion.”

Gukesh, commonly known as Gukesh D, became the third-youngest grandmaster in history at 12 years and seven months. In April, at 17, he stunned the chess establishment by winning the eight-man Candidates tournament in Toronto to become the youngest ever challenger for the world championship, finishing top of a stacked field that included Nepomniachtchi, Hikaru Nakamura and Fabiano Caruana.

That Gukesh was even playing for the world title was a historic achievement. Until April, teenagers had had an indifferent record in the Candidates over the years. Only Bobby Fischer in 1959 and Carlsen in 2006, both then 16, were younger than Gukesh, and both were also-rans.

“My journey, it’s been since the time I started playing chess at six and a half, seven [years old],” Gukesh said. “I’ve been dreaming about this moment for more than 10 years. Every chess player wants to experience this moment and very few get the chance. To be one of them is ... I think the only way to explain it is I am living my dream.”