South Africa’s fragile top six and lack of runs at Test level was exposed as England won a bowler-dominated three-match series 2-1 on Monday, leaving touring captain Dean Elgar with much to ponder ahead of their next five-day assignment in Australia. South Africa made 326 in their only innings at Lord’s in the first Test, but did not manage a score over 179 in their next four visits to the crease as Elgar conceded their brittle middle order is letting the side down.