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
A family has issued an appeal to help find their missing pet turkey - in case he gets gobbled up as someone's Christmas dinner.
A blustery start to the weekend with sunny spells and scattered showers.
Welsh Secretary Stephen Crabb has launched an attack on Labour leader Ed Miliband, saying he "doesn't give a toss about Wales".