guardian angel

noun2

1. •
   A tutelary angel watching over a particular person (and sometimes rescuing them) in monotheistic contexts.

   • I think your guardian angel was working overtime this week. You're lucky to be unscathed.
2. •
   (figurative) A person who benevolently watches over another or rescues them.

   • The guy who came upon the accident scene was my guardian angel. He doused the flames and called the paramedics.