Forlan's lucky break ensures Liverpool feel full effects of epic trek

The good news for Liverpool is that there will be no be 23-hour journey to the return leg; the bad news is that their punchless attack will still be without Fernando Torres and Atletico Madrid will have their star striker Sergio Aguero back on the pitch.

Liverpool must overturn a 1-0 scoreline at Anfield next Thursday to make it to the Europa League final after a goal from former Manchester United striker Diego Forlan defeated them in the Spanish capital last night.

The pre-match debate concerned who would miss their star turn more. Forlan somewhat fortuitously scored the games' only goal in his strike partner's absence. For all the running of Dirk Kuyt and Steven Gerrard, a tired Liverpool side toiled in vain without Torres.

The Liverpool manager, Rafa Benitez, again erred on the side of caution by pairing Javier Mascherano alongside Lucas Leiva in a midfield that was missing the cup-tied Maxi Rodriguez. They shielded a defence that would be spared the threat of the suspended Aguero but included the former Manchester United striker Forlan and former Arsenal winger Jose Antonio Reyes.

Kicking toward their most vocal supporters who had unfurled a giant, "We'll be champions again" banner – a sentiment shared by Liverpool's visiting fans – Atletico set a ferocious early pace and after nine minutes they were ahead.

Jose Jurado broke down the left and crossed. Sotirios Kyrgiakos missed the centre and it reached Forlan on the edge of the six-yard box. For a moment the dual Golden Boot winner must have thought he was back in the Premier League as he clumsily miscued his header, but the error served to help him. The ball dropped loose and he reacted first to sweep it past Pepe Reina and Jamie Carragher on the goal-line.

Liverpool should have been level on 17 minutes but when Yossi Benayoun scored from Kuyt's through ball the offside flag was raised in error to cancel out the equaliser.

Gerrard was having to do the work of two men, playing off struggling frontman David Ngog and dropping deeper to make up for the creative deficit in the centre of Liverpool's midfield. He carried the fight to the home side smashing a shot into the side-netting, then playing in Ngog, but his first touch was awful and the chance was gone.

With Kuyt and Benayoun having to track the runs of Atletico Madrid's attacking full-backs, Liverpool carried little threat going forward and on 32 minutes there was almost a repeat of the first goal. A ball over the top of Glen Johnson sent Jurado away but this time the England full-back dealt with the danger.

At the other end Ngog continued to struggle, missing an attempted scissor kick as Gerrard continued to carry the greatest threat storming through on 35 minutes but running into a wall of Atletico defenders.

At last there was some assistance a minute later as Johnson made his first foray down the right. He was found by Gerrard but failed to deliver a telling cross.

Liverpool's lack of punch up front was summed up just before the break when Simao Sabrosa sent a free-kick into the visitors' wall but when they broke away it was Mascherano who was furthest forward and he was soon caught, albeit illegally.

Liverpool started the second half brightly with Ngog holding the ball up for Gerrard. He looked to have gotten away from the home defence but Luis Perea raced back to hook the ball away.

On 52 minutes Forlan was back in Premier League mode and this time there was no second chance. The flag stayed down as he ran on to a long ball from Reyes but he miskicked with only Reina to beat.

The pace had slowed somewhat – Liverpool with a 23-hour journey from Runcorn to Madrid still in their system and Atletico with 50 games already played in theirs. With the fatigue gaps appeared in both defences. Benayoun broke clear and Perea made another crucial tackle and Atletico broke immediately to so nearly make it two.

Tomas Ujfalusi crossed from the right and Simao connected at the far post only for Reina to push the ball brilliantly over his crossbar. Reyes was enjoying the open spaces and again lost his marker, sending a pass inside Agger that Jurado did not have the pace to run on to. Reyes then sprayed a perfect ball out to the left and Simao ran on to it only to send his cross beyond Forlan in the box.

Just after the hour Benitez ended a tough night for Ngog replacing him with Ryan Babel. The Dutchman went out to the right flank, with Kuyt sent to plough the lonely furrow left by the Frenchman.

Liverpool's failure to score an away goal would satisfy the home side and Atletico's inability to add a second would send Liverpool home feeling the final was still in their grasp. But that sort of caution had not spread to Kuyt, who probed down the left drawing another tackle from Perea. He was then put through by Mascherano but forced wide and could only hook the ball back towards Gerrard whose volley did not trouble David de Gea.

Kuyt was found a way through again but, forced wide, he could only hook the ball back towards Gerrard, whose volley did not trouble De Gea.

With the home support shaking their crumbling stadium with a wall of noise it was still Liverpool who looked close to scoring next. Babel raced down the left and Gerrard laid the cross off to Kuyt, who couldn't finish.

Atletico pressed on the break and Ujfalusi shot from distance but the home side were forced to settle for a one-goal advantage and had to escape a late penalty shout from Kyrgiakos who looked to be tugged at the far post.

Atletico Madrid (4-2-3-1): De Gea; Ujfalusi, Perea, Dominguez, Antonio Lopez; Assuncao, Raul Garcia; Jurado, Simao (Valera, 77), Reyes (Camacho, 90); Forlan (Salvio, 85). Substitutes not used Asenjo (gk), Juanito, Cabrera, Borja

Liverpool (4-2-3-1): Reina; Johnson, Carragher, Kyrgiakos, Agger; Lucas, Mascherano; Kuyt, Gerrard, Benayoun (El Zhar, 83); Ngog (Babel, 64). Substitutes not used Cavalieri (gk), Aquilani, Degen, Ayala, Pacheco.

Referee L Duhamel (France).

Second-leg details

Thursday 29 April:

Fulham v Hamburg (7.45pm, ITV 4)

Liverpool v Atletico Madrid (7.45pm, Five)

Final: Wed 12 May (7.45pm, Hamburg)