Liverpool sought an instant response but, after being found at the far post by Glen Johnson’s deep cross, Yossi Benayoun couldn’t direct his header on target.

Benitez’s side had been the victims of some debatable decision in the 2-1 defeat at Benfica in the previous round, and were on the wrong end of another here on 18 minutes.

Dirk Kuyt’s throughball may have been miss-hit, but it fell invitingly for Benayoun who ran on to finish beyond Atletico keeper de Gea only for celebrations to be cut short by an assistant referee’s flag for offside. Television replays showed the Israeli was clearly onside.

Moments later, an excellent pass from Lucas Leiva put Steven Gerrard into space inside the Atletico area but, with the angle narrowing, the Anfield skipper struck his shot into the side-netting.

Rocked by the blow of Forlan’s early goal, Liverpool had taken a while to regain their composure but ended the half the stronger, enjoying the greater possession without ever giving de Gea any real scares.

But Atletico, although largely on the defensive, continued to be a threat and four minutes before the interval Tomas Ujfalusi scampered away from Daniel Agger before excitedly thrashing an angled effort wide.

Only a fine sliding tackle from Atletico centre-back Luis Perea prevented Gerrard from reaching the penalty area after a typically lung-busting burst shortly after the break.

But the second half belonged to the home side.

They came close on 52 minutes when, after Mascherano gifted possession to Jose Antonio Reyes, the former Arsenal man lifted a ball over the top to Forlan who made a complete hash of his attempt.

And Liverpool were indebted to their goalkeeper shortly afterwards, Ujfalusi crossing to the far post where Johnson slipped to allow Simao a drive Reina did well to turn over.

With the visitors struggling to make any inroads, Atletico finished the stronger and when Ujfalusi’s shot was only parried by Reina, an alert Carragher produced a fine clearing tackle before Forlan could pounce.

Now Benitez’s side must produce a third Anfield fightback in a row to guarantee Hamburg and not Madrid is where they European campaign reaches its conclusion.