When your opponent is dazed, hold R1+R2 util your opponent recovers. When he wakes up, release those buttons and you will unleash the super punch.

Enter one of the following as a player name at the Career Player creation screen. Press Circle at the Pre-Fight Ranking screen to save the boxer for career and exhibition modes.

Fighter             Career Name
Alien               ROSWELL
Ed Mahone           ED MAHONE
Gargoyle            GARGOYLE
Jermaine Dupri      JERMAINE DUPRI
Marc Ecko           MARC ECKO
Marlon Wayans       MARLON WAYANS
O                   O
Shamcko The Clown   SHAMACKO
Tim Duncan          TIM DUNCAN
Q-Tip               Q TIP

Enter "MINIME" as a player name at the Career Player creation screen. (To disable Cheat type "RESETPASS".)

Enter "THROB" as a player name at the Career Player creation screen.

Press Triangle + Circle + X Square during the match to kick your opponent in the midsection.

Press Down + X (using the analogue stick) after being knocked down.

Intentionally disqualify your fighter in exhibition mode to unlock Mills Lane.

Press R1 and R2 and any punch and you will do a illegal move but beware, too many will get you disqualified:
Triangle = head butt
Circle = kidney punch
Square = elbow
X = low blow