Alireza Firouzja ambled out of the playing hall like he had stepped out for a casual walk in the evening. Sporting a green jumpshirt and gold-rimmed glasses, he would have looked like a tourist if it hadn’t been for the people jostling around him, recording him on their phones. His laidback demeanour hid the fact that he had just defeated Gukesh D on the world champion’s home soil in a nail-biting 69-move brawl in the second round of the Chennai Grand Masters tournament.Just a couple of months ago, the sport had confronted unusual scenes of Firouzja playing against Fabiano Caruana and Javokhir Sindarov while sprawled on a hotel bed at the Superbet Chess Classic in Bucharest due to an ankle injury. Eventually, he had withdrawn from the tournament. He then competed at Norway Chess on a wheelchair, mostly with his right leg propped up on a pillow.Before the Chennai Grand Masters started, he revealed that he needed extensive physiotherapy to finally start walking without support. He’s now doing a lot more than walking. He’s striding forward, with two wins in two rounds — results that have given him the sole lead in one of the strongest classical tournament fields ever assembled in India.Also Read | Chennai Grand Masters: Gukesh held to a draw by Nihal Sarin in opening gameHis first-round victory had been over Pranesh, who is playing in one of the most big-ticket tournaments of his career. But on Friday, in a battle between a boy who became the king and the boy who was prophesied to be the prince but never quite got there, Firouzja slayed the world champion.It was a game riddled with errors from both players as the evaluation bar swung like a pendulum. Firouzja had a slight edge by move 27, then made what the engine dubbed as an inaccuracy on the next move. One move later, Gukesh erred. Advantage Firouzja. By the 31st move, Gukesh was in a lost position and had just over a minute on his clock. His rival had two.Gukesh, whose forte is his calculation skills, is not known for his prowess in low times. Firouzja, whose superpower is his intuition, is a beast when the time is low. But the 20-year-old is a patron of lost causes. He did not become a champion by waving the flag of surrender when he was in trouble. Gukesh did what Gukesh is known to do. He fought himself out of the hole.On move 33, Firouzja blundered. The eval bar fell to the centre. It was anyone’s game now. Tension enveloped the board, evident by how Gukesh’s right foot was quaking at the speed of his thought. As Gukesh’s time had grown thin, that right leg was running a marathon. The left leg was yet to get out of bed.Story continues below this adAlso Read | Why Javokhir Sindarov’s biggest rival will help him prepare to face GukeshOver the table, even Firouzja, who is known to wriggle his way out of tight windows of time, was having to pause and think. A speed demon on the board was made to hesitate. More than once, the most laidback chess player in the world reached out a hand over the board but froze, his hand hovering just inches over a piece, his mind the only thing in motion.More blunders from both players followed. The evaluation bar was like a teenager jumping rope. By the 39th move, Gukesh was down a pawn, a disadvantage that he carried into the endgame until he eventually surrendered. But before that resignation came a dance of the knights, with both players using their sole horse on the board to attack and defend at the same time.By the 69th move, Gukesh gave up.The defeat meant that Gukesh was at the bottom of the eight-player standing with half a point along with Pranesh. Between Firouzja and Gukesh lies the rest of the field with one point apiece.Once hailed as a likely successor to Magnus Carlsen’s throne — with the Norwegian himself saying that he was interested in squaring off in a world championship only if Firouzja played — classical chess results had not gone Firouzja’s way. In fact, the Norway Chess tournament was the first classical tournament he had played in almost six months. He had missed out on qualification for the Candidates in March-April earlier this year, and had skipped the FIDE World Cup in Goa at the end of last year.Story continues below this adBut Firouzja had emphasised that classical chess was not unimportant for him.Also Read | At Chennai Grand Masters, another Gukesh vs Nodirbek Abdusattorov battle loading“Each tournament I choose to play in, I have a goal for that tournament. Unlike others, I don’t look at things like ‘I have to be here at the end of the year’. I am here in Chennai which means I am trying to win this tournament,” he had told journalists before the tournament started.Given what he has managed to accomplish over two games in Chennai, he might just complete that mission.