Liverpool, trailing 3-1 from the first leg at Anfield, stunned the Blues with two first-half goals from Fabio Aurelio and Xabi Alonso, who scored a penalty.

Chelsea's defensive frailties, exposed so clinically by Bolton in the Premier League at the weekend, looked like costing them a place in the last four as Liverpool, without their talismanic midfielder Steven Gerrard, threatened to pull off another miracle.

But the Blues looked home and dry after producing a sensational comeback of their own - scoring three times in the second half to lead 6-3 on aggregate at one stage.

Yet this incredible contest took another twist when Liverpool scored twice in as many minutes through Lucas and Dirk Kuyt to leave them just one goal adrift of an incredible victory.

However, Frank Lampard's second in the 89th minute secured a 4-4 draw on the night and a date with Barcelona.

The home side had been outplayed in the opening 45 minutes and had barely threatened to get on the scoresheet despite coach Guus Hiddink's pre-match assertion that Chelsea would go for more goals.

They had to wait until six minutes after the break for the goal which eased the growing pressure on their ambitions of reaching the final in Rome.

Didier Drogba's effort was deflected into the back of the net by Liverpool goalkeeper Jose Reina and a stunning 25-yard free-kick from Brazilian defender Alex then looked to have eased any remaining worries.

When Lampard added a third in the 76th minute the tie seemed to be effectively all over, but Liverpool had other ideas.

Liverpool boss Rafael Benitez had always maintained the first goal would be the most important but when Kuyt collected a pass from Yossi Benayoun and fired over in the 13th minute, he could have been forgiven for thinking that perhaps the task ahead was indeed far too great.

But six minutes later Liverpool were in dreamland when they punished Lampard's push on Kuyt in spectacular fashion.

With everyone expecting the free-kick from the right of goal to be pumped high into the centre of the penalty area, Aurelio stunned everyone, including the flat-footed Petr Cech, by firing his 30-yard effort straight into the bottom near corner of the net.

Referee Luis Cantalejo then rightly awarded Liverpool a penalty when Chelsea's first-leg goal hero Branislav Ivanovic clearly held back Alonso.

The Liverpool midfielder stepped up to beat Cech and suddenly the impossible seemed possible.

Chelsea had Cech to thank for keeping them on level terms on aggregate when he tipped away a header from Kuyt in the final minute of the opening half.

Hiddink's side needed a goal to take the sting out of Liverpool's motivation and it arrived somewhat fortunately in the 51st minute.

Nicolas Anelka, a 35th-minute replacement for the poor Salomon Kalou, crossed low from the right and Drogba got a touch on the ball, with Reina only able to turn it over the line.

Chelsea made it 2-2 on the night when Jamie Carragher's foul on Drogba was punished by a fierce 25-yard free-kick by Alex.

With 14 minutes remaining Liverpool's dreams looked finished when Drogba crossed for Lampard to apply the finish.

But a long-range effort from Lucas was deflected off Michael Essien and beyond Cech in the 81st minute and, somewhat astonishingly, Kuyt put Liverpool 4-3 ahead on the night with a six-yard header two minutes later.

But with Liverpool needing one more goal for a glorious victory in this emotional week on Merseyside, 20 years on from the Hillsborough disaster, Lampard ended a stunning contest with his second of the night in the last minute.

Chelsea will face Barcelona in the last four but only after Liverpool had pushed them all the way in a pulsating contest that was a marvellous showcase for English and European football.

Benitez must have wished Gerrard had been fit enough to play as his contribution may well have been the telling one, on a night when the Reds almost managed to achieve the unthinkable.