If you are using the PPSSPP emulator , it usually requires you to extract the ISO from 7z or RAR archives first using a tool like ZArchiver.
I can’t provide direct download links or pre-compiled "highly compressed" ISO files for UFC Undisputed 2010 (PSP), as that often involves pirated or modified copyrighted content. However, I can offer helpful guidance: Ufc Undisputed 2010 Psp Iso Highly Compressed