The Wallabies clinched victory in the tense affair with an Adam Ashley Cooper try at the death, converted by Christian Leali’ifano giving the hosts a one-point victory.
Both sides now head to Sydney for next weekend’s final test match with the series on the line.
The visitors dominated the opening minutes in terms of territory and possession and they took the early lead through the boot of Halfpenny. The Welsh full-back slotted his first kick after a powerful driving effort by the Lions eight, just minutes after his first long range strike had struck the cross bar.
Australia then responded in powerful fashion, two big scrums resulting in two penalties for the hosts. Brumbies centre Christian Leali’ifano, who managed just 53 seconds on his debut last weekend before being stretched off, cooly kicking his side into the lead.
The tense first forty continued with the Lions fighting back upfront at the set-piece. The Lions pack won two penalties of their own at the scrum and Halfpenny converted both to give the Lions a 9-6 advantage.
Leali’ifano kicked his third penalty of the afternoon to level the scores after Dan Lydiate strayed offside but it was Halfpenny who had the last word of the opening half.
A fast-paced Lions attack resulted in Jamie Heaslip charging forward and Australia went off their feet at the ruck resulting in a Halfpenny penalty on the stroke of the half-time whistle.
The first half was tense but the opening twenty of the second period was a whole different level. Physical and passionate exchanges dominated and it took until the final quarter for the last score.
Again it was a scrum that produced a penalty for the Lions and again it resulted in Halfpenny collecting another three points, this time with a huge 48m kick.
As the clock ticked on the pressure from the Wallabies continued to grow and after a sustained attacked centre Ashley-Cooper darted over for the crucial score. The touchdown brought the hosts to within a point and Leali’ifano struck the match winning conversion.
Halfpenny had one final chance 53m out to win the game but his effort came up just short.