After rallying from the hammer blow of Forlan's first-half opener, levelling through Simon Davies, the Cottagers' hopes of marking the biggest night in their history with the biggest trophy they have ever won lingered long into the Hamburg night, almost to the point of penalties.
But just as he did at Liverpool in the semi-final three weeks ago, Forlan was to have the final word, proving yet again what an aberration in his career those years at Manchester United were.
Single-handedly, the Uruguayan has wrecked the Premier League in this competition.
It was a horrible way for Fulham to end such a momentous journey, and with seven players out of contract at the end of the season and Roy Hodgson being linked with Liverpool, their loud and loyal supporters can only hope defeat does not mark the end in a far more long lasting way.
Sir Alex Ferguson knows a thing or two about management, so when he anointed Hodgson as his manager of the year, ahead of Carlo Ancelotti, whose Chelsea side could do the Double in his first season in English football, it was worth taking note.
What Hodgson has achieved in three seasons at Craven Cottage has been little short of miraculous.
Three games from the end of that 2008 campaign, they were technically relegated, only to drag themselves out of a hole at Manchester City, the platform from which their current success has been achieved.
The momentum has not just built confidence, it has grown immense belief. If you can come back from three goals down on aggregate against Juventus, there is not much left to be fazed by.
So it was when Forlan tapped Atletico ahead.
The Spanish outfit had been marginally the better side, with Sergio Aguero the greatest danger, yet Fulham seemed to have their measure once Forlan had thudded a shot against the post when Danny Murphy needlessly gave the ball away in midfield.
That illusion was shattered when Forlan capitalised on the good fortune that accompanied Aguero drilling a shot into the ground, instinctively prodding the ball past Mark Schwarzer, who could do little other than turn and watch it go in.
Not for a second did Fulham fret or panic. Not on the pitch or in the stands.
Even with Bobby Zamora at far less than full pelt, there was an incisiveness about Fulham's attacks which suggested they would get an opportunity of their own fairly soon.
So it came to pass as Zamora, using strength rather than speed, unsettled the Atletico defence, leaving them ragged as Zoltan Gera tossed over a cross from the right.
Paulo Assuncao stretched to reach it but succeeded merely in nudging the ball on to Davies, who lashed a fierce volley past David de Gea.
The crispness of the finish was nearly matched by Forlan just before the break.
Fortunately for Fulham, Schwarzer reacted to the Uruguayan's goal-bound snap-shot just in time and managed to push it away from his near post.
Both sides, Atletico because of the chance to briefly leap out of the shadow cast by Real Madrid that they are condemned to live under, and Fulham because of the sheer joy of being asked to perform on an occasion such as this, spared nothing in their search for victory.
Another smart effort from Davies brought an equally fine save from De Gea after an hour, by which time Zamora had made way for Clint Dempsey.
After all he has achieved this season, it was sad that Zamora was not able to give his best on an occasion such as this, coming after his rejection of a World Cup call because of the Achilles operation he must have to be fit for next season, they are opportunities that may never come round again.
That knowledge gave Fulham the grit to take the biggest game in their history to extra-time.
Not that they could relieve the pressure around their goal and when Forlan burst to the by-line and Raul Garcia bobbled his cut-back into the path of Aguero, Fulham hearts were in their mouths as the net rippled. Thankfully, it was the wrong side.
In the time that was left, Fulham looked to be the better side.
But forcing the pace brought them no reward, and Forlan sent them to their knees.