TOWN fans have been urged to arrive early for tonight's vital play-off clash with Lincoln City.
Police say supporters must get to the Alfred McAlpine Stadium early even though the game is all-ticket.
And they must not go on to the pitch at any time.
Insp Richard Ogilvie, of Huddersfield Police, said: "A lot of fans turned up late for the recent home game against Mansfield which badly delayed the kick- off.
"We want to warn fans that it is a criminal offence for them to go on to the pitch and if they do, they are liable to be arrested."
Cameras, both inside and outside the ground, will film bad behaviour so fans could even be arrested later.
The winner of tonight's game - which will be decided on penalties if the teams are level after extra time - will go through to the play-off final at the Millennium Stadium in Cardiff on Bank Holiday Monday, May 31.