In Randell’s 37 previous first-class matches, the 30-year-old had only claimed more than five wickets in an innings on two occasions.
Central Districts started the day at McLean Park on 347/8 before eventually being bowled out for 373.
In reply, Northern Districts got off to a bad start when Randell dismissed Henry Cooper with the last ball of his second over.
He returned for his next over to first claim the scalp of former Black Caps opener Jeet Raval before claiming his hat-trick when he had Joe Carter caught behind.
Carter was shaking his head profusely, indicating he didn’t hit the ball before eventually departing.
Randell then got Robbie O’Donnell caught out in the slips before Kristian Clarke became the fifth victim, clipping the ball, which bounced before hitting the stumps.
Randall’s next two balls didn’t having much luck, but in his fourth over, he claimed the wickets of Ben Pomare and Scott Kuggeleijn.
Northern Districts were eventually bowled out for 82.