It's not just a <NOVOTNY INTERFERENCE>.

Position after 36 c1-c6!!:

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The Black e8-queen cannot capture the White c6-rook because <BLOCKADERS DO NOT DEFEND> and the Black e8-queen must <BLOCKADE> the White e7-passed pawn. That is, 36 ... e8xc6 allows the snap mate 37 e7-e8=+ c6xe8 38 e5xe8#.

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Navara's 36 c1-c6!! puts his White c1-rook on a square where it can be captured by three(!) different Black pieces and is not defended at all(!!!).

The tactical point is that not one of the Black pieces that appears to control the c6-square can actually capture the White c6-rook

1) 36 ... b7xc6 37 e5-e6# since the bishop capture <BLOCKED> the 6th rank and stopped the Black a6-rook from <DEFENDING> the e6-mating square

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2) 36 ... a6xc6 37 e5-d5+ c6-e6 38 d5xe6# since the rook capture <BLOCKED> the a8-h1 diagonal and stopped the Black b7-bishop from <DEFENDING> the d5-checking square

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3) 36 ... e8xc6 37 e7-e8=+ c6xe8 38 e5xe8# since the Black e8-queen is needed to <BLOCKADE> the White e7-passed pawn

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Navara's 36 c1-c6!! is so brilliant that I want to give it the illegal !!!-annotation. Oh, what the hell.

And this was a rapid(!) game!