The Black Stars score two goals apiece in each half with World Cup debutant, Jordan Ayew grabbing a hat-trick and captain Asamoah Gyan scoring a goal to seal the win in their final warm-up game in Miami.
Ghana were flawless and took their chances against a strong Korean side.
”It was a good friendly match,” Appiah said. ”It was important we put out a good team. Everyone who paid to come in here got his money’s worth.”
But Appiah said his team have some work to do ahead of their Group G opener against the United States on 16 June in Natal, Brazil.
”It’s fine we won, but we still have some work to do,” said the Ghana coach.
The performance was a big improvement for Ghana, who lost its previous friendly 1-0 to the Netherlands.
”You learn from your mistakes,” Appiah said.
”Korea attacked really well. Playing against players with good pace, you have to be cautious in the back. We made good use of the counterattack chances we got.’
“The scoreline didn’t matter to me. I am looking at the scoreline, I am looking at how best I will prepare my team.”