Jurgen Klopp claimed Brentford 'stretched the rules' at set-pieces after Liverpool's top-four push was severely undermined by a stinging 3-1 defeat in west London.
Liverpool produced an abject defensive performance in going down to an Ibrahima Konate own goal and further strikes by Yoane Wissa and Bryan Mbeumo, leaving themselves 15 points off Arsenal at the top of the table.
The manner of defeat was alarming, with Konate's deflection into his own net coming from an Mbeumo corner and the same delivery leading to two first-half goals for Wissa that were both disallowed for offside.