Joey Leilua and James McManus stretched the lead and centre Leilua almost added his second in embarrassing circumstances when he took a quick tap penalty close to the line and ran straight at three Eels defenders who simply fell off him.
However, the blushes of Daniel Harrison and Ken Edwards were spared when Kelly dislodged the ball as the former Sydney Roosters man crashed over.
But five minutes before halftime the Knights did score a fourth try when Dane Gagai picked off a wayward Jarryd Hayne pass and ran 70 metres before offloading to Darius Boyd.
Hayne, so often the key man for the Eels over the last five years, showed his class four minutes after the restart when he stepped past three players and kicked ahead for Ken Sio to score.
However, it proved to be a rare high point for the wooden spooners as the Knights reacted strongly to run in two quickfire tries through Beau Scott and McManus.
McManus' try came after Hayne butchered a 20-metre restart under pressure from Buderus and the NSW winger made no mistake for his 19th try of a prosperous season.
Leilua added his second after 66 minutes before Akuila Uate and Jeremy Smith getting in on the fun before a Buderus conversion brought up the half century.
Jarrod Mullen then added some extra gloss to the lop-sided scoreline with another try in the closing seconds to make it a record win for the Knights over the Eels.