Welsh centre Jamie Roberts - facing Australia for the first time this summer due to injury - has scored the Lions' fourth try, taking a pass from replacement Conor Murray before galloping home.
Halfpenny makes it another seven points, and the Lions start to celebrate a series win.
More top news
Dan Biggar says the Wales team are enjoying their World Cup journey and will continue to do so after the pool stages.
A cold night ahead with clear spells and mist patches forming by the early hours!
The story of how Wales have taken their qualifying campaign by storm, to put themselves within touching distance of Euro 2016.