Carlos Moya's victory over Henman was gripping enough, but it was later eclipsed by Alex Corretja's astonishing 4-6 6-3 7-6 win over the world No 1 after Sampras had held three match points with the score at 6-5 in the final set.
Moya refused to buckle under the Briton's relentless assault and snatched a dramatic 6-4 3-6 7-5 semi-final victory after trailing 3-1 in the final set. The sole consolation for Henman was that he had been involved in the finest contest of these championship finals so far.
The German Chancellor, Gerhard Schroder, was among the 14,000 crowd who were on their feet to applaud both men at the end of a contest which was always tense but which escalated to a gripping finish.
Henman was unrecognisable as the player who had subsided so lamely against Greg Rusedski on Friday. Having beaten one Spaniard, Alex Corretja, by charging the net, Henman knew well enough there was no future swapping shots from the baseline with another.
So in he went, time after time, daring Moya to pass him. Sometimes it worked, frequently not, as the man from Majorca held his nerve and in the end earned himself a place in the final by passing the incoming Henman with two glorious backhands and then a forehand service return.
Henman was the first Briton to make the semi-finals at this event and will spend a long time this weekend wondering how he failed to inscribe another page in the history of the British game by getting to the final.
If he had done better on getting his first serve into play (his average was again a disappointing 48 per cent) things would have been different. "My serve hasn't been good enough all week," he admitted.
Henman's start was a nervous one and he needed to scramble clear of two break-points in his second service game. But the next time Moya was offered a break-point he grabbed it for a lead which tipped the first set his way.
Rather than letting the disappointment of that setback undermine his resolve, Henman got off to a brilliant start in the second set. The uncomplaining Moya was unlucky to face a break-point when a backhand that seemed to have clipped the line was called out and even unluckier when Henman capitalised with a glorious cross-court backhand. That put Henman 2-0 ahead and it was soon 3-0, precisely the sort of counter-attack Henman had been seeking to mount.
There was a brief wobble at 4-2 when he needed to hit big serves, including an ace, to deny Moya three break-points, but with an hour and a half gone Henman was level at a set-all.
His confidence now at peak level, Henman strode out for the third set hungry to seize the advantage and did so at once, breaking serve as Moya struck a loose forehand into the net. At this stage nothing seemed to be going right for Moya. Volleys were landing an inch or so too long and a doddle of a backhand volley was netted.
When Henman stretched his lead to 3-1 it seemed that there would be no way back for Moya. "But I decided to take more risks and started hitting the ball harder," the French Open champion said. The immediate benefit was three successive games won and now, suddenly, it was Henman who was straining to stay afloat.
He fought off a break-point which would have given Moya a 5-3 lead and then, in this wonderfully see-sawing thriller, reached a break-point at 4-4 which would have left him serving for a place in the final. But, not for the first or last time, Henman was stranded by an inch-perfect lob.
That, as it transpired, was his final opportunity. He had his eyes on taking the deciding set to a tiebreak but Moya had other ideas, as those three stunning winners showed. The two backhands took him to match point and the forehand service return, which hurtled back past Henman as he charged in, was the stake through the heart. The match had stretched over two hours and 19 minutes.
Moya put down his victory to an ability to handle high-level pressure. "Tim hasn't played two Grand Slam finals or won a Super Nine tournament like me. Today I played amazing."
Henman agreed. "He definitely raised his game in the later stages of the third set and came up with some great shots. There was a lot of good- quality tennis and as the match went on the standard got better and better. It was just a question of who could hit the winners at the right time.
"My attacking tactics were right but my execution at times, especially in the first set, wasn't as good as it could have been. My main problem was that all week I haven't been making a great number of first serves."
In addition to prize-money of pounds 190,625, Henman will take away from Hanover a ranking which is now up to seventh in the world. "So although it has been a disappointing end to the year it has been a good ending in other ways. I'm already very excited about next year and if I can continue the progress I've made in the last six months I'm going to be looking to get into the finals of Grand Slams and winning them.
"It has been a jam-packed last six months and although I've really enjoyed it I'm looking forward to having a few weeks off. Then I've got to go to the next level and get into the top five in the not-too-distant future."
Today's match will be the first all-Spanish final in the 29-year history of the event and is a repeat of this year's French Open final which Moya won in three sets.