Luton moved four points clear at the top of the Sky Bet League Two standings as they comfortably ended Grimsby's four game unbeaten run with a 2-0 win at Kenilworth Road.Luke Berry curled in a wonderful 25-yard strike five minutes before the break with James Collins sealing the win just after the hour mark.Luke Summerfield was not far away with a spectacular half volley from range for the Mariners in the 21st minute, while Dan Potts's header was punched over by visiting keeper James McKeown.Collins went close, hooking over from James Justin's cross on the half hour, before Luton took the lead in stunning fashion when Berry fired past McKeown from distance and in the 40th minute.After the break, Danny Hylton was wide from just outside the box, while visiting striker Jamille Matt's shot cannoned against the outside of the post from a tight angle.However, it was 2-0 in the 61st minute when Collins buried a header into the bottom corner from Alan Sheehan's free kick.In the closing stages, Luton could have had a third. Olly Lee was denied by McKeown's shins, Harry Cornick toe-poked wide and Elliot Lee's shot drew a fine stop from the keeper.