Foxes substitute Jamie Vardy came on to score the winner nine minutes from time, the Englishman finding the net for the 11th time in ten league games against the Gunners.
However, the evening might have turned out differently had Lacazette’s header not been ruled out inside the opening five minutes.
The Frenchman’s glancing header from a corner found its way in off the far post but the Gunners’ joy was short-lived as the linesman’s flag was raised against Granit Xhaka.
The Swiss was stood in an offside position in front of Kasper Schmeichel and though he did not actually appear to impeded the goalkeeper’s attempt to keep the header out, VAR upheld the decision.
"I’m really disappointed,” Arteta told Sky Sports. “We had it in our hands in the first half and I don’t know how the hell the goal was disallowed.
"They caught us with space at the back and in that moment we lost the game.
"It is difficult to create spaces with ten men behind the ball, but we should have finished the game better. When it comes to those moments you can’t give away chances at the back.
"We still had some moments after the goal but gave away too many free kicks. The effort that the boys put in, and the pressure the Leicester team put you under, it’s not an easy thing to do but we have to improve."