Head to the marked location to talk to Donovan to get new intel about Tommy Marcano. To get to him, you have to talk first to a man named Alcee Bennett. Head to the marked location in the map to talk to him. Head to the Briar Patch restaurant in the French Ward to find Alcee. Talk to him to trigger a conversation.
Once done, leave the restaurant and drive to Acadia within 4 minutes. After reaching Acadia, enter from the basement door and let Alcee introduce you. Submit to the pat-down and your weapons and equipment will be removed.
Head to the locker room and interact with the locker to change your gear. After getting changed, proceed to the ring where the announcer will introduce you. You’ll be in a boxing match, against Nick “Boom-boom” Beaumont.
The boxing matches from here on is very easy to win if you abuse the Counter button. Basically, press the counter button immediately if the opponent starts to attack and Lincoln will effectively make a reversal which can be followed up by combos. If you can pull off a brutal takedown (by holding the melee button), you can take out the opponent instantly. Otherwise, you can pummel the enemy with counters and punches until Lincoln finishes them off automatically. Boom-boom is fast and likes to close in the distance. He will also push you away when you get too close then follow up with a dirty sucker punch. As long as you counter properly, you wouldn’t have problems dealing with him. After every match, you can either insult the crowd or work them up.
Next opponent is Bobby “Beautiful Brawler” LeDoux. This big guy is slower than your previous opponent which makes it easier to predict his attacks. As usual, counter then follow up a barrage of combos. In case he blocks you, do a reversal to continue with the offensive until Lincoln finishes him off.
For the last fight, you’ll be facing Gravedigger Vaughn. He’s also slow but more aggressive. However, he has openings whenever his attacks are countered so if you can execute a brutal takedown, you can end this fight immediately. After the battle, head back to the locker room to trigger a cutscene.