It might be stretching a point to say Leeds played well - and it was a poor-quality game - but they were resilient, gutsy and committed in defence.
When a stronger Tigers side eased into an 8-0 lead by the end of the first quarter, a big home win looked on the cards.
But Leeds grew in confidence and were the better team for long spells either side of half-time, when the gap was down to just two points, though - inevitably given their half-back situation - they lacked attacking options.
Castleford scrambled well in defence, but were well below-par from the time of their second try onwards; they made a host of basic errors - including not finding touch with a penalty - and were altogether too casual.
Leeds levelled just before the hour mark and looked capable of nicking it, but, not for the first time this year, a moment of poor discipline cost them.
James Bentley was sin-binned for a foul, resulting in a penalty which edged Castleford back in front with 17 minutes left and Tigers scored the decisive try just before he returned.
The RFL’s match review panel will look at the Bentley incident on Tuesday and a charge would rule him out of Friday’s vital bottom-two clash with Toulouse Olympique.
Zane Tetevano is already suspended for that game and Leeds will also be without Blake Austin, who failed a head injury assessment inside the opening 10 minutes.
It was already a big ask for rookie scrum-half Jack Sinfield, but the challenge became even greater after that, when he partnered hooker Kruise Leeming in the halves.
Matt Prior was given an opportunity to rest some knocks and Cameron Smith (dead leg) also missed out, could be available to face the French side.
Sinfield’s fellow teenage debutant Max Simpson was preferred to Jack Broadbent in the right centre and it seems increasingly unlikely last year’s YEP Shooting Star, who is in the final season of his contract, will be at Leeds next year.
Simpson didn’t seem much of the ball, but ran strongly when he did and Sinfield was composed and noticeably grew in confidence as the game went on.
Rhinos had the better of the opening exchanges, but were caught offside near Tigers’ line after seven minutes and the hosts went ahead in the subsequent set, Kenny Edwards looping a pass to James Clare who cut infield through a gaping hole in Rhinos’ defence.
The lead was increased 10 minutes later through some brilliant improvisation by Paul McShane.
He made the initial break which looked like leading to a score for Niall Evalds, but Ash Handley - Rhinos’ best player so far this season - got across to make a sensational try-saving tackle.
However, McShane realised that left Rhinos’ left flank unguarded and kicked into the vacant area for Derrell Olpherts to touch down.
Even with both conversion attempts being missed, at 8-0 Tigers already had a firm grip on the game, but Rhinos got the only other score before the break.
Tigers were denied what initially looked like being their third try, after 24 minutes. Tom Briscoe and Clare competed in the air, the ball bounced in-goal, Bentley failed to ground it and Jake Trueman touched down.
Referee Liam Moore signalled a try, but his video assistant Robert Hicks overruled him, deciding Clare had knocked-on.
Having conceded the first two penalties of the game, a run of four in their favour gave Leeds a leg up in the second quarter, but other than Handley being held up over the line, Rhinos didn’t really look like scoring until the final minute of the half. Tigers’ Mahe Fonua was penalised in possession, for shoving Bentley, Sinfield dabbed a low kick over the line, Jake Mamo made a mess of grounding and Rhyse Martin was handed an easy try which he also converted.
The try brought up Rhinos’ 24,000th point of the summer era, since a Challenge Cup win at Swinton Lions in 1996.
The second half was scoreless for 18 minutes, most of which was played in Tigers’ half, until Martin booted an equalising penalty following a high tackle by Nathan Massey on James Donaldson, moments after Mikolaj Oledzki had been held up over Cas’ line.
After O’Brien’s penalty restored Tigers’ lead, Olpherts had a touchdown ruled out - Hicks confirming Moore’s original ruling of a knock-on by Mamo. With eight minutes left, Tigers finally managed to breach Rhinos’ defence when Liam Watts rampaged over from Trueman’s - dubious - pass, O’Brien converting. Leeds, though, refused to give in and Martin combined with Handley to score his second try which he also improved, two minutes from time.
Never before in Leeds’ history have they won only one of their opening 10 competitive games in a season, but this spirited display - following on from the draw against Huddersfield Giants last Thursday - will give the new coach, exected to be unveiled this week, something solid to work with. From Tigers’ perspective, being able to win when playing this poorly was a positive sign. The penalty count finished 7-6 to Tigers, who received the last four. They had four set restarts to Rhinos’ one.