Norwich City came away from Elland Road with a hugely significant three points, a result that saw them move above Leeds to go top on goal difference. They were well worth the 3-1 scoreline on the night.
The visitors took the lead from Mario Vrancic's 20-yard free-kick, which took a slight deflection off the wall to take it past Kiko Casilla.
From there, Leeds United never looked comfortable chasing the game. Unable to carve open clear opportunities, Norwich were clinical as Teemu Pukki scored his 18th goal of the season to double their lead.
Marcelo Bielsa made a couple of attacking substitutions at half-time, but they were unable to change the flow of the game.
Vrancic's second put the game beyond doubt 15 minutes before full-time, as an injury-time goal from surprise substitute Patrick Bamford proved little consolation for Leeds.
Norwich show a new dimension
Daniel Farke's men did remarkably well to keep their shape, never obliging as Leeds did their best to spread the ball and pull them apart.
Norwich have the worst defensive record in the top six and rarely keep clean sheets, but made Leeds - so often a force to be reckoned with when they click into gear - look unimaginative and imprecise going forward.
The majority of the ball was played in Norwich's third, as Bielsa's men had their customary 60%+ possession, but it was they who dominated in terms of chances. Always choosing the right moments to press, they often forced Leeds backline into mistakes. This proved the case for their second goal, as Pukki was switched on enough to poke home Vrancic's deflected strike.
Norwich's back four looked increasingly comfortable as the game wore on, in spite of Bielsa introducing potential game-changers Jack Clarke and Bamford, who have both been responsible for winning Leeds points coming off the bench this season.
Ben Godfrey was particularly impressive, with an ability to read the game beyond his 21 years of age. The young centre-half always stepped out when needed to, with a positional awareness that saw him well-placed to cut out anything threat inside the area.
As Leeds pushed up to get back into the game, they always ran the risk of conceding a third, which eventually came in the 78th-minute, as Vrancic registered his second with a scuffed low effort somehow evading a possibly-unsighted Casilla.
Norwich couldn't register a clean sheet in the end, with Bamford unmarked for a close-range header, but that was little more than a blot on an outstanding performance.
Fine line between anxiety and ecstasy at Elland Road
A fortnight ago, Leeds put in one of their best performances of the season under the Elland Road floodlights.
The idea, as made obvious by Leeds social media calls to arms, was to replicate that - and the home crowd responded with a deafening noise at kick-off for this top of the table clash. Selling out within a couple of hours, this was the club's most anticipated match in years.
That night, Leeds beat Derby 2-0 as the breaking 'Spygate' controversy instilled a siege mentality in the raucous, jubilant crowd. With such a symbiotic relationship between team and fans, it's difficult to speculate who was responding to who. Either way, that night was pure ecstasy for the considerable home support.
This one wasn't.
Bielsa's men started with intent, putting some good moves together in midfield and pressing well in the final third, looking to set the tone as they did against Derby.
But that was all undone by an early mistake from Pontus Jansson. Conceding the opener was borne out of overconfidence, as the Swede lost the ball nonchalantly, followed by an excessive eagerness to atone as he fouled to give away an unnecessary, dangerously-placed free-kick.
As the season enters the third and final act, teasing something that's felt like an eternity to arrive, undelivered after several false dawns, anxiety inevitably enveloped the home crowd. You could almost feel the thousands of "are we blowing it?" inner monologues whirring in tandem.
There were parallels with Liverpool's timid display at Anfield in midweek, as a mental clarity looks the biggest hurdle to overcome for the top two division's title challengers.
The successive errors that lead to Pukki's goal, Norwich's second, look to have been brought on by that anxiety, with Adam Forshaw particularly culpable as he gave the ball away in a dangerous area.
While Leeds were dominant in possession, often in the opposition half, they were limited to tame long-range efforts which failed to liven the crowd.
Decisions deemed injustices were the only things to produce a spike in volume, notably after Tim Krul was given a yellow card after he came rushing out like a decaf Harald Schumacher, catching rather than clattering Tyler Roberts.
Norwich did well to extinguish any chance of a second-half fightback. Leeds' late consolation could only give pause to a sell-out crowd that were winded from the gut-punch of watching opposition come to Elland Road and outclass their team. This promises to be a long few months for Leeds.