Arsenal went five points clear at the top of the Premier League table with a dramatic last-gasp win at Luton.In a chaotic game, the Gunners took the lead on three occasions but were pegged back every time before Declan Rice won it with the last kick of the game.Mikel Arteta will still likely be frustrated at the manner of the performance, with Arsenal guilty of sloppy errors for all three of Luton's goals.Gabriel Martinelli lost his man for Luton's opener and David Raya was beaten far too easily for the other two.