Head to Local Battle. There you will find start a tournament.
You can do this solo.
Settings:
Select Character: First Match only
Select Starting Position: Every Match
No. of Players: 1
No. of CPUs: 2
CPU Strength: 1
Time Limit: 300 Sec
No. of Matches to Win: 1
Start Tournament
There is only 2 matches.
The CPU VS CPU fight will auto battle and end in a second.
You just need to play your fight. Jimmyclitchman confirms his achievement still popped after losing.
Achievement Unlocked. You just need to play a Tournament.