His goal and the quality of Dan James' finish provided some evidence that Patrick Bamford's prophecy may prove true when he told his podcast partner Joe Wilkinson that week: "Every time that I've been in a team when we haven't gone up, we've done it the next year. Hopefully that's a good omen!"
Farke admitted after the game that more additions were needed and wingers Largie Ramazani and Manor Solomon duly arrived before deadline day.
A candle of hope had been lit.
Two defeats in their 12 matches after the Sheffield Wednesday win had seen Leeds cruise up towards the top two places.
A comfortable 2-0 win over Sheffield United in October had seen Blades boss Chris Wilder call them the best team in the division and by late November it was becoming hard to argue.
Adam Pope
BBC Radio Leeds reporter
Then Swansea City head coach Luke Williams said before the game he fully expected Leeds United to be promoted having gone so close last season but he could not have predicted the glut of goals which followed on a weekend where Storm Bert had wreaked havoc throughout south Wales.
The fact Leeds scored four times was a big deal because the Swans had not conceded more than a single goal in 17 matches up to that point.
Gnonto came off the bench to score the winner very late on after Leeds let a 3-2 lead slip, having earlier twice come from behind. It showed the fighting spirit was there if not game management and sent Leeds top for the first time this season on goal difference.
Willy Gnonto takes in the adulation from the Leeds fans after his last-minute winner at Swansea
Sometimes the wisest thing to do is nothing at all.
With his side in scintillating form, Farke had been adamant he would only look to make additions if they were better than what he had.
Southampton striker Cameron Archer was linked with a move but it came to nothing and, two days before the transfer window closed, the Whites demolished struggling Cardiff 7-0.
Transfer deadline day passed without a single addition.
Adam Pope
BBC Radio Leeds reporter
It felt like Leeds had gambled. Everybody knew the squad as it stood had the ability to win the league but the point was how much of it would still be standing if injuries hit?
How costly would it be not to sign a number nine with Patrick Bamford a long-term injury, or a proper number 10, and not to provide cover at centre-back? These were the big questions in the wake of a window which saw their main rivals strengthen while Leeds were left lighter.
Two days later United went to in-form Coventry City and won 2-0 and it could have been 12. Farke and the owners had rolled the dice. It looked like it could be paying off.
Ao Tanaka headed Leeds into the lead late on at Sheffield United before Joel Piroe's thumping finish sealed the win
Leeds headed into mid-February in great shape before back-to-back Monday night challenges against top-four rivals, Sunderland and Sheffield United.
The former took an early lead at Elland Road through Wilson Isidor and with time running out it looked like the Whites were going to fall to a damaging defeat.
Centre-back Pascal Struijk was the unlikely hero as the Dutchman, on as a sub, headed in two wicked deliveries from fellow replacement Joe Rothwell to produce a dramatic turnaround.
Leeds would head to Bramall Lane top of the table.
Adam Pope
BBC Radio Leeds reporter
Five points clear at the top and for many it felt like promotion was guaranteed.
After the game left-back Junior Firpo gave a timely reminder that everyone should just calm down. He talked of the need to "stay humble", that the job was "not done yet". He was right and he was also correct about how powerful Leeds were late on in games.
Once the Dominican Republic international had deservedly equalised with a thumping header with 18 minutes remaining, Blades boss Chris Wilder and assistant Alan Knill looked spooked on the touchline.
Defeat looked inevitable for the hosts from that moment and Leeds did not disappoint. A precision header from Ao Tanaka and a rip-snorter from Joel Piroe ignited euphoria in the away end inside an otherwise empty Bramall Lane on full time.
Leeds had seen it through in a massive game.
Illan Meslier has not featured for Leeds since his mistake in the 2-2 draw with Swansea
Promotion had felt inevitable after those raucous Monday night wins in February but March brought the kind of jeopardy Whites fans had feared.
The unbeaten run which stretched back to a 1-0 reverse at Blackburn on 30 November was ended on 9 March by a 1-0 defeat at struggling Portsmouth.
Although Millwall were despatched 2-0 three days later Farke's men then needed to recover from a horror start at QPR to escape with a 2-2 draw.
The international break looked like it had come at a good time to reset and refocus, with the lead over third-placed Burnley cut from seven points to just two.
Managerless Swansea arrived in town in poor form and hopes were high of a return to winning ways.
Adam Pope
BBC Radio Leeds reporter
Gnonto looked to have won the game from the bench late on to send Leeds top and rescue goalkeeper Illan Meslier after a calamitous drop under no pressure had gifted Swansea an equaliser.
But Meslier eventually cost his side top spot and himself a place in the side thereafter by allowing another equaliser to squeeze through him from a tight angle in the final seconds.
The credit for his earlier penalty save was completely eradicated as it felt like a defeat and the Frenchman's litany of errors was now too severe for him to keep his place.
"You have to suffer a little bit," Farke told the press after the game and that, despite March seeing them slip from first to third amid a run of one win in five games, he was "100% confident his side would be playing Premier League football next season."
Many were sceptical, others called for a head which was keeping composed when some were being lost.
Karl Darlow was given the gloves for the draw at Luton the week after the Swansea debacle.
There was little he could do to stop Isaiah Jones netting the opener before James levelled with a fine finish but some fans were unhappy that Farke called the point against the strugglers a good result as their own poor run stretched to one win in six.
However, Sheffield United's unexpected loss at Oxford later that day, when a win would have moved them four points clear of the Whites, proved Farke's words correct.
The battling 1-0 midweek win at play-off chasing Middlesbrough ended a run of three straight draws and, as the Blades lost at home to Millwall, Leeds had turned third back to first in no time at all heading into the final five matches.
Leeds players showed their appreciation after the 2-1 win over Preston
Adam Pope
BBC Radio Leeds reporter
This was a battering for Preston make no mistake.
Leeds backed up a gritty win at Middlesbrough to produce a cracking performance under intense pressure to hit the top of the table. Joel Piroe should have had a hat-trick but his battling and link-up play were intrinsic to United carving Preston apart. With James injured it needed him and Manor Solomon to step up. The latter was unplayable at times and scored a curling pearler in the first five minutes to set Leeds on their way.
Once in front Leeds do not lose and so it proved.
The news filtering through from Home Park of a third consecutive defeat for Sheffield United created an incredible atmosphere inside Elland Road for the latter stages of the match.
Coinciding with concrete news from the club's owners that, in tandem with the council, steps were definitely being taken to expand its capacity the famous old stadium provided a timely reminder of how unique it is as a footballing experience.
A free bar was laid on afterwards to say thank you to the fans - pints and points on a pivotal day.
