Northampton signed off in style at Sixfields with another victory as they beat Luton 2-0.The champions won it with first-half goals from Zander Diamond and John Marquis.Cobblers took just four minutes to break the deadlock when Diamond headed home Danny Rose's far-post corner.Luton's Danny Green then fired wide with a low drive before he was stretchered off with a bad injury moments later.Ricky Holmes saw his effort deflected over but Joe Pigott should have equalised from Pelly Ruddock's cross when he headed over with the goal at his mercy.Cobblers doubled their advantage in the 36th minute when Marquis rounded off an excellent move by turning in John-Joe O'Toole's low cross.David Buchanan tested Elliot Justham as Cobblers took control of the game and Sam Hoskins struck the upright just before the break.Hoskins should have scored straight after the restart after being set up by Marquis but he shot wide from close range.Pigott struck a post moments later before firing wide as Luton looked to get back into the contest but Cobblers created more chances with Justham saving from Hoskins and O'Toole firing over.