Tactical players will notice White's hidden mating motif with Re7-e8 which is not dangerous in the moment since the square e8 is covered two times by the black pieces.
BUT, if Black moves for example 26.- Nd5?? it becomes evident. 26.- Qxa3 would be good. 27.Bxd5 27.Qf5! would now have won on the spot since Bxf5 is not possible (27.- Bxf5 28.Re8#) and the knight d5 is pinned (27.- Nf6 28.Qxa5); 27.- Nd8 28.Rxd7 +- 27.- cxd5 28.Bxc7? Once again Qf5! would be the winner. 28.- Qxc7? 28.- Qxa3 29.Re1 is far better 29.Qf5! Finally White found this move. 1-0
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