Despite play being delayed early on after fireworks were thrown on the pitch, the visitors were ahead inside the opening 10 minutes as Cas Peters managed to get past Marvin Peersman with a weaving run into the box, leaving him to slot into the bottom corner.
The visitors doubled their lead just after the half hour mark though as Bryan Smeets curled the ball into the box from a free kick, setting up Bart Straalman for a header at the near post.
Youssef El Jebli came close to making it 3-0 just a couple of minutes later, but a reaction save from Leonard Nienhuis kept his powerful strike out, before striking the post with a long-range effort just before half time.
Against the run of play, Cambuur got back into the match in the final seconds before half time though as Overgoor found himself in space just outside the box, leaving him to drive the ball into the back of the net.
The woodwork was tested again at the start of the second half as Cambuur pushed for an equaliser, but Overgoor's finish was just wide, while Wessell Dammers headed just wide from a corner moments later.
The home side were back on level terms within 10 minutes of the restart though as a mix-up in the box resulted in Nathaniel Will turning the ball into his own net.
De Graafschap attempted to restore their lead late on after winning a free kick in a promising position, but Robin Propper's header was glanced wide from the resulting set piece.
Things got worse for Propper a couple of minutes later though as he reacted angrily to a decision from the assistant referee, and having already been booked earlier in the second half, he was shown a red card, leaving the visitors a man short for the final five minutes.
Despite being down to 10 men, the visitors continued to push for the winning goal, and were awarded another free kick with a couple of minutes remaining, leaving Tarfi to unleash a powerful strike directly from the set piece to secure the win for De Graafschap.
Despite the win, De Graafschap remain bottom in the division, while Cambuur sit 17th, just two points clear of this evening's opponents.