Jose Mourinho's side came within a quarter of an hour of elimination before Terry's 76th minute header put them through 5-4 on aggregate at the end of a night of enthralling drama at Stamford Bridge.

Trailing 2-1 after a bitterly disputed first leg, Chelsea stunned the Spanish league leaders by scoring three times inside the first 20 minutes to take control of the tie in the most spectacular fashion imaginable.

But two goals from Ronaldinho allowed Barcelona to haul themselves back to 3-2 before the break - a score that would have been enough to put them through on the away goals rule.

It could have gone either way after the break but it was to be Chelsea's night.

When Damien Duff floated a corner in from the left, Barcelona made the fatal mistake of allowing Terry a free run from the edge of the box and the Chelsea skipper planted his header powerfully beyond Victor Valdes, though the visitors protested justifiably that Ricardo Carvalho held back their 'keeper.

It mattered not to Terry, who less than a fortnight ago held aloft the League Cup after beating Liverpool in extra-time.

"That performance is up there with the best of them," said the England centre-half.

"We started brilliantly - it was like a runaway train - and pressed them hard because we had been told that they didn't like it and it showed.

"However by half-time it wasn't looking great. Nevertheless we came out fighting and pressed them once again which put them off their rhythm.

"To beat a great side like that says it all about the guts and quality of our team," purred Terry.

The elegant session of keep-ball with which Barcelona opened the match offered no hint of what was to ensue after their most reliable guardian of possession, Xavi, was hustled off the ball by Lampard, just inside Chelsea's half.

The England midfielder immediately sent Kezman into space on the right, from where the Serbian's astute low cross found Gudjohnsen, who cut inside Gerard before flipping his shot past Valdes.

Lampard might have made it two four minutes later, when he fired John Terry's knockdown over the bar from the edge of the six-yard box.

He quickly made amends by pouncing to score Chelsea's at close-range after Valdes, wrong-footed by a deflected Joe Cole shot could only parry it back into play.

The home supporters barely had time to squeeze in a jubilant rendition of 'Boring, Boring Chelsea' before Duff added a third, finishing off a move that proved Barcelona don't have a monopoly on slick passing.

Carvalho started it on the edge of the Chelsea box, Kezman continued it with a deft lay-off for Cole, whose pass split the Barcelona centrebacks, allowing Duff to squeeze between them at full tilt before earning Duff just enough space to squeeze his shot low past Valdes.

Samuel Eto'o, with a chip that Cech touched over the bar at full stretch, and Ronaldinho, with a header from the resulting corner, both went close before Paolo Ferreira's handball allowed Barcelona to get back into the match.

Ronaldinho hammered the spot kick low past Cech's right hand and suddenly the mood of the evening was transformed.

A superb save from Cech kept out a viciously swerving free-kick from Deco but there was nothing that the giant Czech goalkeeper could do about Ronaldinho's wonderfully improvised strike seven minutes from the interval.

Not that there seemed much danger when the Brazilian was confronted by an imposing wall of defenders on the edge of the penalty area.

But with a minimal back-lift, he still conjured a moment of pure inspiration as he crafted a shot that curled into the far corner, leaving Cech motionless.

An extraordinary first half almost yielded another goal when Cole, Chelsea's outstanding outfield performer by some distance, beat Valdes only to see his shot come back off the post.

Chelsea were first to threaten after the break, Lampard's deflected drive spinning wide.

Lampard's header from the resulting corner drew a fine save from Valdes but Chelsea had even more reason to be grateful to their goalkeeper, who produced superb stops to keep out a shot from Gerard and a bullet header from Carles Puyol.

At the other end, the Barcelona captain threw himself into Gudjohnsen's path to block the Icelander's shot after Kezman had found him unmarked beyond the back post.

It looked like it could prove a costly miss for Chelsea, particularly when Iniesta's shot came back off the post into the path of Eto'o.

But the Cameroon striker snatched at his shot and the ball ended high in the stand, giving Terry his chance to claim a victory that will live long in the memory of every Chelsea fan who witnessed it.