At the Reykjavik Open today, Sopiko G. (Mrs. Anish Giri), rated 2363, had just played 17...Ng3 against GM Stefansson (2566).
Although Stockfish likes White after either 18. Rg1 or 18. Nxg3, Stefansson decided to play 18. f4??...after which Sopiko just captured the Rook, and the GM resigns.