Du Preez 's score gave South Africa a four - point lead .
That meant Wales , with goal - kicking flyhalf Dan Biggar off the field for a head injury assessment , needed a try to regain the lead in a brutal and see - saw contest .
Du Preez 's score gave South Africa a four - point lead and that meant Wales , with goal - kicking flyhalf Dan Biggar off the field for a head injury assessment , needed a try to regain the lead in a brutal and see - saw contest .