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Nepomniachtchi In Semifinals After Niemann Blunders Mate-In-1
Ian Nepomniachtchi and Hans Niemann are equally shocked when Niemann blunders mate-in-one.

Nepomniachtchi In Semifinals After Niemann Blunders Mate-In-1

Colin_McGourty
Colin_McGourty
Staff
| 29 | Chess Event Coverage

GM Hans Niemann knocked out GM Maxime Vachier-Lagrave and won the first game against GM Ian Nepomniachtchi, but he's out of the 2025 Weissenhaus Freestyle Chess Grand Slam Play-In after blundering mate-in-one at the end of a thrilling blitz playoff. In the Semifinals Nepomniachtchi will face GM Vladimir Fedoseev while GM Javokhir Sindarov takes on GM Yu Yangyi, with the last spot in the $750,000 Weissenhaus Grand Slam up for grabs.

The Semifinals and Final take place on Wednesday, January 8, starting at 11:00 ET / 17:00 CET / 9:30 p.m. IST.

Knockout Bracket

Each match is played over two 15+3 rapid games. Ties are decided by two 5+2 blitz games and, if needed, a final armageddon game. 

Let's take a look at how the four semifinalists qualified.

Nepomniachtchi 2.5-1.5 Niemann

By far the most intense quarterfinal saw newly-minted World Blitz Champion Nepomniachtchi take on Niemann, who has been one of the most vocal critics of his opponent sharing the title in New York with GM Magnus Carlsen. Niemann had that on his mind before their online match. 

Nepomniachtchi also couldn't forget New York, since as he commented afterward, "I didn’t think I would make it too far because I’m terribly jet-lagged after New York." He said he'd woken up at 5 p.m. before the games started at 7 p.m.

His day could have been over fast as, after a quiet first game against qualifier GM Oleksandr Bortnyk, he admitted he thought "OK, that's it," when he blundered on move two of their second game, with 2.Bf4? running into 2...e5!.

In the unusual freestyle chess position, the black queen was suddenly coming to b4 with check before grabbing the pawn on b2, and White was in deep trouble—note the knight on a1 is undefended in the starting position.

Nevertheless, Nepomniachtchi somehow went on to win, with Bortnyk losing control and ultimately blundering a fork near the end.

Until Nepomniachtchi's preceding move, Bortnyk could play his queen to b1, but not anymore, and his event was over. He asked a question you could get rich if you have an answer to.

Niemann's path to the Quarterfinals was also rocky, with Vachier-Lagrave close to winning on move three of their first game in what the commentating GM Daniel Naroditsky called a "bullet-brawl opening."

Niemann exchanged queens at the right time, however, and rescued a draw, while in the second game he seized the initiative from the opening and trapped the French star's queen. 28...Nxd5! was an inventive try born of desperation, but Niemann didn't put a foot wrong as he went on to win the game and match.

That set up a mouth-watering quarterfinal, which didn't disappoint.

The first game was an unmitigated disaster for Nepomniachtchi, who was tempted by a plan to grab the b2-pawn.

There were multiple refutations, including taking with the pawn on f6 and then the queen on e6, as played by Niemann, but it's notable that even after falling into the "trap" with 13.Kxb2 Na4+ 14.Ka1 Qa3+, the computer prefers White after 15.Nf1!.

Niemann was visibly enjoying himself and went on to win in 18 moves.

That was the lowest point for Nepomniachtchi, who later commented:

"After I lost the first game against Hans, I finally woke up. I was barely awake, honestly I was struggling. I drank a lot of tea, I ate a lot of sweets, but it never helped, but closer to midnight I felt like suddenly there is some energy."

After I lost the first game against Hans, I finally woke up.

—Ian Nepomniachtchi

What followed was a fine win for Nepomniachtchi which is our Game of the Day and has been analyzed by GM Rafael Leitao below. 

That meant the fun continued, and the first blitz game was the wildest encounter of the match. "I was struggling out of the opening every time," said Nepomniachtchi, but when he took over late in the game, it seemed certain he'd power to a win.

Instead Niemann, getting down to a couple of seconds at one point, defended brilliantly to rescue a draw.

It was understandable that Niemann was elated at his win.

The second blitz game was every bit as tense. At first Nepomniachtchi seemed to have a big edge out of the opening, then Niemann took over, and for most of the game it was about Nepomniachtchi trying to extricate himself from a tricky position.

On move 38, however, he decided to make a one-move threat to deliver checkmate—and then couldn't believe his eyes as it worked! 

He quipped in the post-game interview, "At least I found my mate-in-one, so probably my endless training in Puzzle Rush paid off!"

At least I found my mate-in-one, so probably my endless training in Puzzle Rush paid off!

—Ian Nepomniachtchi

The remaining Quarterfinals were all surprisingly decided by a 2-0 score, and there was a pattern—in each case, the winner was the player who had come through the Round of 16 in two games, while the loser had faced a long battle that had gone to a blitz playoff.

Fedoseev 2-0 Duda

Fedoseev had talked about how much he enjoys freestyle chess (Chess960) after winning the Swiss qualifier with an unbeaten 8/9, and his fantastic form continued as he was the only player to score 4/4 in the Knockout. His first victim was world number-14 GM Leinier Dominguez, who went astray in a tricky pawn endgame in their first game before blundering on move nine of the second.

Duda, meanwhile, was involved in a huge fight with GM Parham Maghsoodloo that was summed up by their first game. Maghsoodloo was winning, but one slip allowed Duda to take over before eventually delivering checkmate. 

Maghsoodloo hit back convincingly to force a blitz playoff, but that's when Duda, a two-time World Blitz Championship runner-up, took over, winning the next two games.

The mental exertion, however, may have impacted the Quarterfinal, where it was all about Fedoseev.

23.c4! was a crisp temporary piece sacrifice by Fedoseev, who was also giving up a pawn with check in order to get his rook to the seventh rank. What followed was a smooth conversion, with just one slip along the way. 

Duda seemed to have good chances of hitting back in the second game, but after a tactical oversight, suddenly Fedoseev took over to clinch the match. 

Sindarov 2-0 Praggnanandhaa

It was a good day for the four players who had fought their ways into the Knockout through the Swiss, with 19-year-old Sindarov remaining unbeaten this week. His first game against world number-nine GM Wei Yi was quiet, while in the second he used a similar e5-trick to the one we saw earlier from Bortnyk to win a pawn and ultimately the game.

Gukesh and Anand will be the two Indian players in Weissenhaus, after Praggnanandhaa was knocked out in the Quarterfinals.

GM Praggnanandhaa Rameshbabu had an altogether tougher task against his compatriot GM Vidit Gujrathi, since despite winning smoothly in the first game, he blundered in the second, moving a rook from d1 only to get the other rook trapped on f1.

There was no way back, though Praggnanandhaa did then take over in the blitz, winning both games to book a spot in the Quarterfinals.

Sindarov found a key intermediate move to seize a big advantage and win the first game. While Praggnanandhaa was initially doing well in the second, he would ultimately be hit by two rook sacrifices.

Sindarov needed just a draw, but the position was too good not to play to its logical conclusion.

Lazavik 0-2 Yu

The longest Round-of-16 match saw GMs Denis Lazavik and Wesley So go all the way to armageddon. They'd made four draws, but after a 15-move draw by repetition in the second rapid game, the first blitz game was a 98-move fight in which So escaped from a completely lost position.

So then won the bidding for the armageddon with an offer of four minutes, and needed only a fifth draw to clinch the match. Everything seemed to be going perfectly when he'd not only equalized but was dominant. However, needing only a draw does strange things to a player—it was a death by a thousand cuts as inaccuracies crept into the U.S. star's play until he allowed one of Lazavik's pawns to break free.

More twists followed before the 18-year-old was able to give checkmate.

Yu, meanwhile, pounced on a mistake by GM Liem Le in their first game to take the lead and then made a draw from a winning position in the second game. The Chinese star would surprisingly have an even easier time in the Quarterfinals.

Lazavik was on top in the first game when he blundered with 29.Kc3?. It was such a rare occurrence that the watching IM David Pruess exclaimed, "I've never seen his I've-made-a-mistake face!"

It turned out that after 29...Rd8! the pin on the d-file was fatal, with the pawn coming to e3 stopping any attempts to consolidate. Lazavik needed to win the second game on demand, but instead it was Yu who totally dominated from start to finish.   

That leaves just four players still in the running for a prestigious and potentially lucrative spot in the Weissenhaus Freestyle Chess Grand Slam, with the Semifinals (Nepomniachtchi vs. Fedoseev and Sindarov vs. Yu) taking place on Wednesday. Don't miss it! 

    How To Watch
    You can watch the 2025 Freestyle Chess Grand Slam Weissenhaus Play-In on the Chess24 YouTube or Twitch channels. You can also check out the games on our dedicated events page.
    GM Daniel Naroditsky and IM David Pruess hosted the broadcast.

    The Freestyle Chess Grand Slam starts with the $750,000 first of five legs in Weissenhaus, Germany, on February 7-14. Nine players, including GMs Gukesh Dommaraju, Magnus Carlsen, and Hikaru Nakamura have already been invited, while the remaining spot will be decided in a Play-In on Chess.com on January 4-8. Then 12 players move straight to a 16-player Knockout with two-game 15+3 matches, while the last four players qualify from a nine-round Swiss Open played at a 10+2 time control. All games are played in freestyle chess.  

    Previous coverage:

    Colin_McGourty
    Colin McGourty

    Colin McGourty led news at Chess24 from its launch until it merged with Chess.com a decade later. An amateur player, he got into chess writing when he set up the website Chess in Translation after previously studying Slavic languages and literature in St. Andrews, Odesa, Oxford, and Krakow.

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