It was another Nimzo-Indian defence and the players quickly moved through the starting 15 moves of theory.
But after Yifan’s 15…Rc8, the reigning World Champion Anna Ushenina got into a deep though trying to find the plan to continue the game.
Her solution was not the best though. She rushed to move the queen away from the rook on the c-file, but at the same time released the tension with the knight on e4. Yifan jumped on the opportunity and claimed the advantage with 18…Bxa4!
The fine tactical point is that after the intended 20. Qxa4, black first inserts 20…Nc3! and then 21. Qb4 Qxd4! 22. Bxf7+ Rxf7 23. Qxd4 Ne2+, the fork finishes the game.
Another line that had to be calculated correctly was 21…Rxc4 and now if 22. e7 Qd3 23. exf8=Q+ Kxf8 24. Qa3+ Rc5! 25. Bd6+ Kg8 26. Bxc5 Ne2+ 27. Kh1 Nxf2+! 28. Bxf2 Qxa3.
The game didn’t last much longer and Ushenina resigned on move 24. Hou Yifan is now leading in the match 2,5-0,5.