This plugin disables damages in a 1vs1 (enabled automatically and disabled only if players joins Blu/Red team).
It's usually made for server owners using the dodgeball gamemode on Team Fortress 2 but you can use it everywhere.
Cvars:
tf2_godmode1vs1 - (default: 1) Enable/Disable godmode on the server.
Installation:
godmode-1vs1.smx goes into addons/sourcemod/plugins/ godmode-1vs1.sp goes into addons/sourcemod/scripting/ tf2_godmode1vs1.cfg goes into cfg/sourcemod/ (anyway this file is auto-generated)