The gap widened after closest rivals MK Dons were beaten at home by Leyton Orient.
The evening had begun badly for Brighton when they were forced to borrow Leicester's third choice yellow kit after the one they had arrived with was found to clash with the Foxes' traditional blue strip.
But the game ended on a positive note for Brighton, who travelled back to the south coast with an unexpected point in their battle against relegation.
Despite their failure to register another win, one local bookie is so sure that Leicester will be promoted that he's already paid punters who backed them to go up.
After a slow start, City almost had their noses in front on the half hour mark when an Andy King thunderbolt from 22 yards ricocheted off the bar with John Sullivan reacting quickly to block Mattie Fryatt's follow-up shot.
In a quiet first half, Tom Cleverley drove narrowly over and a goalbound Matt Oakley shot was deflected for a corner.
Close to the break, David Martin was almost caught napping by Brighton and needed two attempts to smother Nicky Forster's low drive.
After the re-start, Jack Hobbs almost turned a Dean Cox cross into his own net but Martin kept City level with an instinctive block.
Michael Morrison squandered a fine chance to break the deadlock on 78 minutes when he rose unmarked at the far post to meet a Cleverley cross which he headed wide of the target.
City upped the tempo as the game entered its final phase with Andy King going close when his 22-yard shot was deflected on to a post.
Then in time added on, Fryatt should have won it for City but held his head in frustration after he blazed Cleverley's cross over from eight yards.