After an uninspiring first half at Hunter Stadium on Sunday, the Panthers and the Knights were locked at 6-6 at the break.
But Penrith dominated the second stanza, leaving the Knights to extend their club record losing streak to 15 games.
It also puts Newcastle into the top 10 on the all-time longest losing streak list.
The Knights enjoyed 60 per cent of the possession in the first half, but despite repeated opportunities they could not crack the Panthers' line.