Eagles boss Patrick Vieira looked on course to secure victory over his former club as second-half goals from Christian Benteke and Odsonne Edouard overturned Pierre-Emerick Aubameyang’s early opener.
But substitute Lacazette netted a last-gasp leveller as an entertaining game at the Emirates Stadium ended 2-2.
Lacazette has played just 72 minutes of Premier League football this season and his future remains unclear, with his contract due to expire at the end of the campaign.
But Lokonga felt the French forward showed the spirit the rest of the team required to come back and earn a share of the spoils.
“I think Lacazette did well today,” he said. “He backed me, he backed the team. I think when we come on we have to bring this mentality that Lacazette did.
“I think he brought fire when he came on and that’s what we need to try to do every time somebody comes on.”
Lokonga had replaced the injured Bukayo Saka at half-time and was at fault for Palace’s second goal – losing the ball in midfield before Edouard fired the visitors ahead.
Thomas Partey had already made the error which led to Benteke’s strike and Lokonga was unhappy with the way the Gunners let their lead slip.
“I think they (the goals) are from two mistakes, one of them mine as well,” the 21-year-old midfielder said. “It is an area where I cannot lose the ball, so it is difficult to speak about the goals when I made a mistake.
“It is difficult to say that we started the game well because we only had the goal. I think after that we relaxed too much because we had to look for the second goal, we had to put more pressure on them and we didn’t.
“I want to play the next game as quick as possible. When you play a game like this, you are hungry inside because I made a mistake. I want to play the next game as quick as possible to change everything.”
This was the second time in three games that Palace have conceded a stoppage-time equaliser.
Neal Maupay struck at Selhurst Park to earn Brighton a point in the derby on 28 September and Benteke acknowledges it is something that needs addressing.
“There’s a lot of things going on. There is emotion. We are leading, we are away from home. It’s a tough game and we are tired. There is a lot of things going on,” he told his club’s website, reflecting on Lacazette’s goal.
“But I think it’s no excuse, because it’s not the first time we are dropping points. I think we will learn from our mistakes, but we are learning the hard way.
“I think we are playing the way the manager wants us to play: with intensity, playing football. Now it’s not enough.
“To win a Premier League game we have to be more ruthless, and play with more experience – and stop conceding those late goals.”