The game at the Amex Stadium seemed to be heading for stalemate as both sides struggled for any fluidity, but it came to life in the final stages as first Glenn Murray's 77th-minute penalty kick was saved and then Vicente Iborra put Leicester ahead with seven minutes left.
The defeat means the Seagulls remain six points above the Premier League relegation zone.
Brighton slowly began to turn the screw in a first half initially bereft of clear-cut chances and they might have found a lead when Locadia capped off a fine passing move to lash across the box, where Jose Izquierdo was a fraction away from getting a vital toe to the ball.
"Glenn's been very good for us this season and has scored penalties", added Hughton. "All you can do is react in the right way".
"They got a lift in the last period of the game, following the penalty miss, and that got them the goal".
"It's an opportunity and you either score or you don't".
Claude Puel's Leicester, meanwhile, boosted its chances of Europa League qualification by staying three points behind seventh-place Burnley.
Kasper Schmeichel was at fault for Chelsea's extra-time victor as Leicester was knocked out of the FA Cup last time out, but he was a hero for the Foxes on this occasion.
"I think this save gave a boost for my players and it was the opposite for the opponent because it was hard to accept this situation for them", Puel said.
"It will be tough and they have confidence, but it is the same for us because we play on the back of two good performances".
Little was being created by either side but their cause was not helped by a series of yellow cards for cynical fouls. We will check whether this damage will keep him from playing at Brighton or not. "It wasn't a fantastic game for us".