I Need Help On Quality After Resizing in PSP8

[Mystic Blue]

Pic 1 was opened in PSP8, resized, retouched a bit and saved and the result is grim...

Pic 2 was opened and resized and exported in Serif PhotoPlus 8. Then I opened it in PSP8 and retouched it with Nik filters and saved it with a much sharper result.

Ignore the colour difference it's just the image quality I am concerned about. I am getting the same poor quality with all images just using PSP8. But opening them and resizing them first in PhotoPlus 8 seems to do the trick. I am confused... Any advice would be gratefully received...