Brisbane also finished with 10 players after James Donachie shown a red card for a dangerous challenge on classy Wellington striker Jeremy Brockie.
Backing up their 1-0 upset over Adelaide last weekend, Brisbane move from second bottom into sixth place.
Pre-game talk Mulvey might use the A-League's January transfer window to recruit a back-up striker fired up Berisha, who opened the scoring in the 14th minute by beating defender Ben Sigmund before slotting the ball past 'keeper Mark Paston.
It was Berisha's first open goal since November and the Albanian dropped to his knees and kissed the turf.
Brockie went to the top of the A-League scoring list with 10 goals when his stunning 36th-minute strike levelled scores at 1-1 before halftime as Brisbane threatened to take control of game.
Wellington struggled at times to cope with the midfield creativity of German ace Thomas Broich, the slickness of Mitch Nichols and the height of Erik Paartalu who played a more central role under Mulvey.
Their probing work repeatedly opened up the Phoenix defence as Berisha, Henrique and the ever-dangerous Halloran began running riot.
Brockie's blistering equaliser seemed to rock the Roar's confidence with skipper Matt Smith and Nichols exchanging strong words as they left the field.
"We need to get our emotions going," said Broich of the half-time exchange between his teammates.
Broich said Brisbane had made life difficult for themselves.
"We had so many chances," he said.
Wellington coach Ricki Herbert said facial injuries to both Bertos and Alexander Smith late in the clash meant he would have to send for reinforcements for this weekend's showdown with Melbourne Victory.
Smith, who left the ground holding an ice pack to his left cheek, may have scans for a suspected fracture.
"We've probably got two players who might have cracked cheekbones; we'll wait and see," said Herbert.
"Alex Smith is the other one and it's probably from an elbow so hopefully that's looked at as well.
"He might have scans tonight."
The A-League's match review panel could have a look at one or two incidents from the game including a clash involving Wellington defender Manny Muscat and Brisbane youngster Nick Fitzgerald which infuriated Berisha.
An upset Berisha earned a yellow card, his fourth of the season, for dissent after vigorously confronting referee McGilchrist and gesturing to him with his elbow.
- AAP