There's bad news and good news for Natalia Pogonina's fans. The bad news: she lost today against Mariya Muzychuk and trails their (best of) four game match 1.5-.5. The good news: she trailed in her last three matches as well before winning them, so she can shrug it off as business as usual and come back raring to go. It's not too late for her to win the women's world championship.
Today's game was somewhat strange, in my estimation, as both players - especially Pogonina - seemed to persistently underestimate the importance of controlling the e5 square. In fact, she needn't have allowed White's f4 break in the first place. She stood better in the early middlegame, and one slightly ugly but strong way of keeping control was 27...g5, to be followed by ...Ng6 (and ...Bxg3 the moment White breaks the pin on the knight). Such a position would be almost unloseable for Pogonina.
Instead, she allowed White to achieve 28.f4, after which the pressure would always be on Black to hold. A computer might thrive on this task, but not a human, and very soon Muzychuk had a winning advantage. She missed a chance to deliver an earlier knockout with 45.Ndf5!, when after 45...gxf5 46.R1xf5 Qe7 47.Rh6 Black will get picked apart one piece and pawn at a time. Black's slight material advantage is useless, as the bishop on b7, the knight on c5 and the rooks are playable no-to-almost no role in the defense whatsoever.
Muzychuk missed this opportunity and one or two more chances later on to put a quicker end to the game, but the trend was always on her side and her position was just too much easier to play. Pogonina lasted until move 58 before throwing in the towel.