Indian Grandmaster R Praggnanandhaa suffered a shock defeat after committing an inexplicable blunder from a winning position against Richard Rapport on day four of the Fast Classical competition at the Total Chess World Championship Tour Pilot in Budapest.

The 21-year-old made a late mistake in their first game and was immediately checkmated by Rapport.

As soon as Praggnanandhaa realised his mistake, he put his hand to his forehead, wearing a wry smile in disbelief.

“I don’t think I can play anything worse than that, so it’s fine!” Praggnanandhaa said.

The two drew their return encounter, leaving Praggnanandhaa at the bottom of Group B and it also ended his hopes of qualifying for the title knockouts.

His sister R Vaishali also bowed out of title contention after losing both her games to American GM Wesley So.

The Indian GM has four points from eight games, having lost six matches, won one and drawn one.

Only the top four players from each group will advance to knockout 1 and will fight for the title, while the rest will compete in the classification brackets.

However, Arjun Erigaisi remained in contention after ending Maxime Vachier-Lagrave's unbeaten Fast Classical run.

“It wasn't an easy game but I'm happy to win. I think in general Maxime is very quick under the clock, I'm happy I was able to put pressure on him,” Erigaisi said.

Following a draw in their first game, Erigaisi won the return with White in an endgame to join Vachier-Lagrave on 13 points.

Hans Niemann also moved to 13 points after a win and a draw against Bibisara Assaubayeva.

Niemann won the first game with White, but Bibisara held him to a draw in the day's longest game.

World No. 1 Magnus Carlsen drew both games against Shakhriyar Mamedyarov. Without a win in the group stage, the Norwegian was also eliminated from title contention.

Anish Giri took the outright lead in Group C with a win and a draw against Abhimanyu Mishra. Giri won an endgame with White in their first encounter.

Alireza Firouzja leads Group A on 13 points, while Fabiano Caruana holds a four-point advantage in Group B with 16 points. Dutch GM Anish Giri heads Group C on 13.

Jorden van Foreest joined Duda on 11 after exchanging wins with Andrew Hong.

Hong struck first with Black, but Van Foreest hit back with a win with Black in the return game. The three points apiece leave Hong on nine.

Levon Aronian and Nodirbek Abdusattorov also drew twice. Aronian reached nine points, level with Hong, while Abdusattorov has seven.

Firouzja thus carries a two-point lead into the final pair of group games.

Caruana and Liem Le drew both games, keeping the gap between Group B’s top two at four points. Caruana has 16 from four wins and four draws, while Le remains unbeaten on 12.

Two games remain for each player in the Fast Classic round-robin stage before the final standings determine places in the six knockout brackets.