North Queensland overcame a short turnaround and draining humidity to grind out a 22-14 NRL win over Newcastle in Townsville on Saturday night.
Anthony Mitchell, a match-day replacement for injured halfback Michael Morgan, played a role in all three of the Cowboys' tries as they held out an onslaught by the Knights late in the first half.
The crucial victory, which comes after a hard-fought win over St George Illawarra in Wollongong on Monday night, at least temporarily moves the Cowboys into fourth place on the table.
With a slim finals chance of their own up for grabs, the Knights came out quickest and opened the scoring in the fourth minute through centre Timana Tahu.
The Cowboys then went on to post 18 unanswered points, with Mitchell involved in everything.
The 23-year-old put halves partner Johnathan Thurston into a large gap in the ninth minute to hit straight back at the Novocastrians.
Mitchell was again influential at the 20-minute mark to set up the Cowboys' second try, throwing outside to a roaming Matt Bowen who skipped past a defender to score his twelfth try of the season.
Brent Tate finished off the Cowboys' next try in the play of the match, taking advantage of some brilliant work by Bowen and Mitchell.
The Cowboys' fullback received a bomb a metre out from his own tryline after 27 minutes and beat four tackles before laying off to Mitchell, who passed inside for Brent Tate on the halfway line to go on and score between the posts.
But the Knights hit back late in the first half, pegging one back through Tahu on the half-hour mark before bridging the gap to four points via Dane Gagai five later.
The Knights were not without their chances to take the lead, but squandered three golden opportunities through line breaks only to be denied each time by the video referee.
Two penalties to Thurston were the only points in the second half, in which neither side had any real clear-cut scoring opportunities.
The loss ended any hopes the Knights had of making the top eight.
Knights backrower Chris Houston was taken from the field in the 68th minute after a head knock with Gavin Cooper but medical staff cleared him of any serious injury.