Substitute Hasani had already served warning of his goal threat with a superb free-kick that crashed against Brad Jones' crossbar.
And the Macedonia international’s slaloming run and classy finish in the 91st minute ultimately proved the difference at Brondby Stadion.
Despite Brondby's superior match sharpness - this was the Danes' fourth pre-season game - it was Liverpool who started the better, with Coutinho a constant menace.
Brondby keeper Lucas Hradecky then made fine saves from Coutinho, Brad Smith and Lucas Leiva, but a searing run down the left from teenager Ibe - brought on at half-time - led to Kristoffer Peterson equalising from close range.
Riza Durmisi and Hasani both hit the woodwork with free-kicks as the home side unsurprisingly finished the stronger, yet the latter was not to be denied in stoppage time as he fired home to earn Brondby the win.
