Leeds came within 10 seconds of securing their place in the second phase of the Champions League and sending Barcelona crashing out in a remarkable game at Elland Road.
It took a goal from World Player of the Year Rivaldo deep into stoppage time to deny Leeds their passage and leave Barcelona clinging to their place in the competition.
Lee Bowyer's stunning early free kick appeared to have sent Leeds into dreamland, but it was young goalkeeper Paul Robinson who had emerged as the real hero for 93 minutes.
A Leeds victory would have meant much more than mere revenge over a side who had inflicted a humiliating 4-0 opening game defeat on David O'Leary's side.
The draw still excorcised many of those Nou Camp ghosts, but David O'Leary's side were left feeling robbed at the final whistle.
O'Leary had claimed before the game that victory over the Spaniards would provide him with his greatest achievement as a manager and match the joy he felt at winning his first league championship title at Arsenal.
His team didn't let him down, turning in a performance to warm the hearts of the Elland Road fans, as well as their manager.
But, in truth, Barcelona's second-half chances merited a share of the spoils, even if the manner of their survival was cruel in the extreme.
Robinson had produced a string of fine saves to keep the Spaniards at bay, but was powerless to stop Rivaldo's late low drive after Gerard's shot had bounced back off a post.
Fernandez Abelardo's foul on Mark Viduka wide on the left gave Bowyer the sight of goal he needed, and Barcelona's French goalkeeper Richard Dutruel was caught in no-man's-land, groping at thin air as Bowyer's bending drive flew over his head and into the top right-hand corner of the Barcelona net.
It gave Bowyer his seventh goal of the season, his fourth in the Champions' League and, crucially, provided the foundations on which Leeds were able to build their planned route to stage two of the competition.
Dutruel made some ammends for his early howler with a fine save low to his right to deny Alan Smith on 10 minutes but, at the other end, Leeds stand-in Robinson was even more impressive.
The England Under 21 keeper ensured a respectable scoreline against Manchester United on Saturday and his heroics continued against the Spaniards.
First, Robinson produced a spectacular reaction save to palm away Rivaldo's close-range header midway through the first half.
The young keeper then made an even more impressive stop in first-half injury time, springing down to his left to push out Rivaldo's deflected free kick just as the Brazilian's strike seemed bound for the back of the net.
Robinson's heroics continued in the second half, despite heavy rain ensuring that handling became a nightmare for the keepers.
Time and again Robinson proved equal to anything Barcelona threw at him - and time and again it was Rivaldo who was doing the throwing.
Charged down
Nineteen minutes into the second half, Robinson was down smartly at his near post to push away another Rivaldo free kick, Xavi's shot on the rebound charged down by the brave Ian Harte.
Two minutes later, the World Player of the Year was denied by Robinson again from another free kick after Dacourt had fouled, but 15 minutes from time Rivaldo seemed to have finally broken through.
The Brazilian latched on to a half clearance and returned a shot with interest, though it took a wicked deflection for the Brazilian to finally get past Robinson.
Leeds' hearts were broken, but the sight of a raised linesman's flag provided a quick fix as Gerard was spotted in an offside direction right in front of Robinson.
The setback sparked a Barcelona onslaught as constant as the driving rain, but Leeds produced a resolute defensive display to continually frustrate the Spanish club.
In the end, it wasn't quite enough, as Rivaldo finally broke through to leave Leeds requiring a point from their final match in Milan on November 8.
Failure to avoid defeat against the group leaders, coupled with a Barcelona win over Besiktas, would send O'Leary's side crashing out in the cruellest of circumstances.
Teams:
Leeds: Robinson, Kelly, Harte, Woodgate, Mills, Bowyer,
Dacourt, Bakke, Matteo, Smith, Viduka. Subs: Milosevic, McPhail,
Jones, Hay, Burns, Evans, Hackworth.
Barcelona: Dutruel, Reiziger, Abelardo, Alfonso, Cocu, Rivaldo,
Sergi, Xavi, Simao, Enrique, Puyol. Subs: Arnau, de Boer,
De la Pena, Gerard, Gabri, Dani, Santamaria.
Referee: Terje Hauge (Norway)