Black has won two pieces for the rook; the slight material gain is incidental, however. More importantly, Black has eliminated White's 2 best pawn blockaders. Rooks are inefficient blockaders of pawns: when a pawn advances against a rook, the rook's power is progressively reduced, since the rook can then move only backwards. Whereas a bishop or a knight directly in front of a pawn looses none of its range, since they both shoot around the blocked pawn.
26. Kg1xf2 d4
Black disdains the h4 pawn for three reasons. 1. Black's material advantage is already sufficient to force a win; the win of another pawn on the edge will not increase the strength of the central pawn mass and will only distract the dark-squared bishop from his duties supporting the central pawn mass. 2. It is time to activate the light-squared bishop which has been sitting passively on b7; it now comes into the game with a crucial tempo, driving the White queen to a less favorable square. 3. Removing the h4 pawn might allow White to get some counter-play by piling up rooks on the h-file and threatening the Black king position.
27. Qf3h3 Bb7d5
The bishop is heading for c4 to block the file for the White rooks and prepare to advance the e-pawn.
28. Rd1c1 Bd5c4 29. Rd3d1 e5
The preparation phase is now complete. The next phase is: rush forward with the e-pawn. Black now controls nearly all the squares in front of the pawn: e4, e3, and e2.
30. Qh3f3 e4 31. Qf3f4 e3 32. Kf2e1 e2 33. Rd1xd4
If Rd2, then Bxh4+; 34. g2-g3, Bg5 and Black wins the rook anyway plus the h-pawn. Better to get a bishop and pawn for the rook than loose a rook and pawn for the bishop.
33... Bf6xd4 34. Qf4xd4 Re8d8 35. Qd4c5
Hoping for a queen trade, which Black will refuse. The queen should have gone to f2.
35... Qe7xh4
If the White queen were already on f2 now, White could have held out a little longer. As it stands, however, Black finishes the game with a tactical shot. White's next moves are forced.
36. g3 Qh4xg3 37. Qc5f2 Rd8d1 38. Rc1xd1
38. ... PxRd1(R or Q)+; 39. Kxd1, QxQf2 and mate soon after. 0 - 1