Crooklands found themselves behind after two minutes from a soft penalty, well converted by Tom Divver.
Five minutes later striker Jack Gardner had to leave the field with a hamstring injury.
After 22 minutes Tom Reede put Hurst Green 2-0 up and Cassies, who had been a yard off the pace, had given themselves a big uphill task.
After this they settled down to playing some football and thought they had pulled one back with two minutes to go but the Hurst Green keeper pulled off a tremendous close range save from Dave Mansergh.
After 10 minutes of the second half Mansergh got round the back of the Hurst Green defence and crossed to Kieren Clark who headed just wide.
Crooklands were playing better at this stage and Ben Phizacklea also went close.
It was not Cassies day, however, when following a good raid down the left hand side from Samuel Hayes, Danny Mort put Hurst Green 3-0 up on 74 minutes.
Cassies continued to plough forward but the keeper made a succession of good saves in particular from Glyn Caine and Ben Phizacklea.
Crooklands did pull one back with five minutes to go when a Ben Wheeler shot was stopped by the keeper but Kieren Clark followed up and put the rebound away.
The second half performance was much improved and not quite getting the rub of the green but Crooklands had paid the penalty from a slow start to the game.
Both goalkeepers made good saves with the home keeper much busier in the second period in a game which went from end to end.
Jasper Carey and Glynn Caine were to the fore for Cassies with Kieren Clark showing some skillfull touches.