This may sound tricky, but its not. I got this in my very first multiplayer match on Tomb Raider.
I played Ranked Rescue, where downs/deaths are common.
Basically, just play the game. There isn't a legitimate way to manipulate this, you just have to be the only person not downed or incapped at any point during the round. The achievement will pop as soon as this criteria is met.
I'd recommend just staying out of the main firefights, and try to skirt the main battles.
It is luck based, however, you will get lucky incredibly quickly.