Title says it all!
As for me, in my Pokémon Gold version, my team that defeated Trainer Red were:
with Leftovers as a held item
with Spell Tag as a held item
with Nevermelt Ice as a held item
with Blackbelt as a held item
with Soft Sand as a held item
with Miracle Seed as a held item
All the Pokémon on my team were LEVEL 53
Did I struggled defeating Red? YES!
It took me, I believe, 9 attempts to finally beat him LOL
So what was your team? LET'S SHARE PEOPLE!