Brighton manager Chris Hughton felt Glenn Murray’s second-half penalty miss spurred Leicester on to victory at the Amex Stadium.
Striker Murray saw his 77th-minute spot-kick saved by Foxes goalkeeper Kasper Schmeichel before late goals from Vicente Iborra and Jamie Vardy compounded Albion’s misery.
The 2-0 defeat means Hughton’s Seagulls remain just six points above the Premier League relegation zone in their battle for survival.
“(It was) frustrating and disappointing but that’s top level football. It was a game that I couldn’t see us losing,” said Hughton.
“If you can’t see your team losing, then it’s about going to win the game.
“For the strengths that they have, I thought we nullified them very well, had chances ourselves.
“But you’ve got to put them away in those moments otherwise what can happen is what happened today. Probably the lift that they got from the penalty miss saw them go and get the first goal.
“I think it’s a moment that changes the game. If we’d scored, I think we would have gone on to win the game. But it happens.
“I didn’t see us drop from that moment but what I did see is them get a lift.”
Brighton’s unsuccessful spot-kick was awarded by referee Chris Kavanagh when Jose Izquierdo was sandwiched in the box by Leicester pair Harry Maguire and Wilfred Ndidi.
Spanish midfielder Iborra then headed home Ben Chilwell’s fine delivery with six minutes to go and, after midfielder Ndidi was dismissed for a second booking following a challenge on Shane Duffy, England striker Vardy tapped home the second in stoppage time.
Hughton refused to attach any blame to 13-goal top scorer Murray.
“Glenn’s been very good for us this season and has scored penalties,” added Hughton.
“All he can do from that is react in the right way.
“There’ll be nobody more down than Glenn will be.
“It’s an opportunity and you either score or you don’t.”
Leicester’s success boosts their Europa League aspirations and they stay three points behind seventh-placed Burnley, who won at West Brom.
Foxes manager Claude Puel also felt Schmeichel’s penalty save was the turning point in the game and praised his keeper for bouncing back from his error in the FA Cup defeat to Chelsea.
“I think this save gave a boost for my players and it was the opposite for the opponent because it was difficult to accept this situation for them,” Puel said.
“I’m happy for Kasper, especially after he was unlucky against Chelsea. He showed always his quality and he’s a fantastic goalkeeper.
“We didn’t play well today but it’s a good result for us and a good reward for Kasper also.”
Frenchman Puel, however, was unhappy with Ndidi’s second booking in the 87th minute.
“For me it’s not a yellow card, it’s not a foul, he touched the ball,” he added.
“It’s harsh to lose this player in this moment. It’s harsh to lose this valuable player for us for the next games.
“The most important thing today, of course, is the result. It wasn’t a fantastic game for us.”