One of the NRL pre-season favourites after last year's run to the preliminary finals, the Warriors are now 14th after just three wins from their opening nine games.
Most concerning for coach Andrew Webster would be the teams they are succumbing to, with the Newcastle defeat following losses to St George Illawarra and Gold Coast.
The Auckland-based club also drew with Manly four weeks ago, starting their recent poor run.
Dylan Walker's try got the Warriors back in the contest. (Dan Himbrechts/AAP PHOTOS)
Webster's men looked off from the start in the wet on Sunday.
In the first 20 minutes alone they gave away five penalties and four errors, handing the Knights their first try through Tyson Gamble when Charnze Nicoll-Kolkstad failed to clean up a Jackson Hastings kick.
And while the Warriors got back into the match through a Dylan Walker try, they were then denied twice through two crucial calls.
The most contentious of those came just before the halftime break, when Dallin Watene-Zelezniak dropped a ball over the line while being tackled in mid-air by Greg Marzhew.
Shaun Johnson argued with referee Chris Butler that a penalty try should have been awarded, given Waetene-Zelezniak would almost certainly have scored without the contact.
"I agree with you, but our interpretation which is comp-wide, is we don't give penalty tries in those circumstances," Butler could be heard responding.
"I'm not disagreeing with you, but we have to be consistent through the year."
The Warriors were then denied again after the break, Jackson Ford ruled to have obstructed Jackson Hastings in the lead up to a Watene-Zelezniak touchdown.
And while they drew level through a penalty goal, the Warriors handed the lead back through a soft try to Daniel Saifiti with 16 minutes to play.
The visitors then failed to get a kick away on two of their last three good attacking opportunities, before a last-ditch Johnson kick was batted dead at fulltime.
The result hands the Warriors their worst winless run of Webster's tenure, with tough matches against the Sydney Roosters and Penrith in the next fortnight.
For the gritty Knights, they are up to 11th on the ladder after back-to-back wins following last week's defeat of the Dolphins - both without injured star Kalyn Ponga.
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