This achievement can fortunately be unlocked offline.
To set this up, go to:
- Exhibition -> Gauntlet.
- It is important that you press
before confirming as it defaults as a 4 man gauntlet.
- Select 5 or 6 on the match settings tab, select your superstar and run the gauntlet. EDIT, thanks to SuperS0nicSam's comment:
If you want an even easier, way of getting this achievement in a very quick, 2 minute match... you can change the ring out time to 3 seconds while setting up the match.
During the match, exit the ring, attack the opponent on the outside and re-enter the ring to get them counted out very quickly and easily. Best done on Eas difficulty to avoid any reversals.
The match itself consists of you facing off against 5 (or 6 if you're a masochist) superstars in consecutive 1 on 1 bouts.
I'd recommend using the healing power-up when needed as it can get tough as the match rolls on. Be sure to use your signature move when possible as well (
with a full blue circle).
Should you be successful, you will unlock the achievement. You can play it on easy, so do that for an easy ride.