A-League Wrap: Brisbane extend lead, Perth hold Wellington
Mike Mulvey's side went into the game at the Suncorp Stadium knowing they could extend their lead at the summit with a victory following Western Sydney Wanderers' derby defeat to Sydney FC 24 hours earlier.
And Albanian forward Berisha struck his ninth and 10th A-League goals of the season to tighten Brisbane's grip on the title.
Berisha opened the scoring on 22 minutes from close range, before then doubling his team's advantage from distance six minutes after half-time.
Argentine forward Jeronimo Neumann pulled one back for Adelaide with a superb goal in injury time, but that proved little more than a consolation as Brisbane made it four wins from their last five home matches.
Sunday's other A-League fixture saw bottom-placed Perth Glory end their four-game losing run with a 1-1 draw at Wellington Phoenix.
Kenny Lowe's men were on course for just their second away victory of the season when former Chelsea, Arsenal and Tottenham defender William Gallas scored his first goal for the club 11 minutes before the interval.
However, Costa Rican striker Kenny Cunningham had other ideas, as he made it three goals in his last three appearances late on to snatch a draw for Wellington, who remain eighth.