Spain coach Jose Antonio Camacho says his side's three straight wins in Group B will stand them in good stead for the knockout phase.
South Africa made Spain fight all the way in Daejeon, but a brace from Raul and a fine Gaizka Mendieta free-kick were enough for a 3-2 win.
And Camacho was pleased to have topped the group with a 100% record.
"We were already in the round of 16 but it was very different
finishing first or second," he said after the match.
"We now have more time to rest but from
now on it will be sudden death.
"We had a great group phase which we haven't had for a
very long time.
"But nobody will give anything away now."
As group B winners, Spain next play the Republic of Ireland, in Suwon on Sunday.
"Ireland didn't lose any games in their group matches.
are a very compact team. It will be a very good game for both of