"In the first-half we did a rather good job, but in the second-half we complicated life a little.
"But that's okay - we've only been here for a few days.
"I know we can play better - it's in 12 days (when England start their World Cup campaign against Sweden) that we will play very well."
Eriksson reserved special praise for Bayern Munich midfielder Hargreaves, who played the entire match and gave an effervescent performance in the centre of midfield.
"He played very well, he's hard working and has improved his technique a lot.
"You must have two players who can play in that place and we have that.
And the Swede credited England's opponents, who are co-hosting the World Cup.
"South Korea impressed me a lot," Eriksson said. "They were very aggressive and I think they can be a surprise in the World Cup."
England goalscorer Owen echoed the sentiments of his coach.
"The main thing today was getting a run-out and coming away with no injuries," Owen said.
"That was more important than the result. We were just feeling our way in and getting used to the climate and conditions.
"We've got another game under our belts and we are going to improve.
"We knew they were a good side and they proved they could play a bit."
Trevor Sinclair, who is still on stand-by as England wait on the fitness of Kieron Dyer, was disappointed with his own performance though.
"It was a bonus getting on but I found it difficult," the West Ham winger admitted.
"I gave the ball away a lot and I'm disappointed with my performance."