Imposter: The last few moves of this interesting clash of minds must have been played at bullet speed, as there were some howlers on both sides. After <51.Rxb7>:
click for larger viewBlack opens up his own King wing with <51...fxg5> instead of keeping the lines closed with something like <51...f5>, or <51..Qd5> nudging the Rb7 and keeping a hairy eyeball on h1...(51...Qd5 52.Rxa7? Qd4!). Anyway, after Black's <54.Qh4> (diagram) 
click for larger viewWhite has a mating attack with <55.Rf1+>, but plays <55.Qf3+>, instead... 
click for larger view<55...Qf4> is forced, and now after <56.Qh5>: 
click for larger view<56...Qf6!> holds. Unfortunately, Black plays <56...Re7??>, which was mate in four after <57.Rc8+>: 
click for larger viewbut instead White finds <57.Qxh6+>, which is still a forced win, especially after Black's <57...Kg8>: 
click for larger viewwhich this time allows a mate in three with <58.Rc8+ Rd8 59.Rxd8+ Qf8 60.Rxf8#> or mate in four starting with the move White actually played, namely <58.Qg6+>: 
click for larger viewHowever, in what must have been an absolutely mad time scramble, White forgot that Black's Re7 can move, and after <58...Kf8>, he played <59.Rh1??> expecting to be able to mate next move, but along came and after <59...Rxb7>, the second last move before the time control, Black is winning. White gives a check on his 60th with <60.Rh8+>: 
click for larger viewand just as Black is about to move his King to the safety of e7, and a won game...his flag must have dropped. Talk about drama. | 
Kibitzing
sac: 59.Rh1