 Ireland had been within three points at half-time as Jonny Sexton punished England indiscipline, but the visitors were dismantled in a one-sided second half.Replacement Ben Youngs sealed the win with an opportunistic darting run from a tap penalty as the wheels came off the Ireland set-piece in the last quarter.South Africa overpowered a game England to win the first Test of the three-match series in Durban.