Perpetual check

In the diagram you see a position from Leko - Akopian (Jermuk 2009). Black now played the interesting move 52.- Bxh4. This must have been the moment where Peter Leko was thinking: Are you kidding? I mean if White simply takes the bishop he is a rook up (the black d-pawn will be stopped somehow?). Those must have been the thoughts when Leko really played 53.gxh4? (53.Ra3 Bf6 54.Rxd3 seems to be more logical.)

After 53.gxh4 Qd4!! (brilliant idea by Akopian) Black is going for a perpetual check. Black's plus is that the white rook on a7 cannot help defending. 54.Qe3 (protecting the rook a7). 54.- Qxh4+ 55.Kg2 Qg4+ 55. Kg2 Qg4+ 56. Kf1 Qd1+ 57. Kg2 Qg4+ 58. Kh1 Qh4+ 59.Kg1 Qg4+ 60. Kh1 Qh4+ 61. Kg1 Qg4+ 62. Qg3 (finally; the only move to prevent the perpetual check) Qd4 (if the rook a7 now moves d2 is coming; the square a1 is not available for the rook, so d1-Q is threatening) 63. Qc7 Qg4+ 64. Qg3 Qd4 65. Qe3 Qg4+ 1/2-1/2