Manchester United are in commanding position to reach the Champions League semi-finals after last night's triumph - but Roma midfielder Daniele De Rossi is refusing to write off his team's chances.
Goals from Cristiano Ronaldo and Wayne Rooney gave United a 2-0 quarter-final advantage in the first leg in Rome.
De Rossi knows Roma's hopes of advancing to the last four of Europe's elite club competition will be hanging by a thread when they arrive at Old Trafford for the return leg in a week's time.
'Manchester United have proved what a great team they are,' he said.
'It's clear that for us it now becomes an almost impossible task.
'But for better or for worse, we have shown in the past that we are able to pull surprises.
'We have a duty to go to Manchester with the belief that we can get a result and progress to the next stage.
'We still have to go to Manchester - and we will give our best.'
A mix-up between Roma goalkeeper Alexander Doni and defender Christian Panucci allowed Rooney to knock the ball home for United's second goal in the 66th minute.
'It hit us hard,' said De Rossi.
'It came at the worst possible time, just when we were playing at our best and we looked closer to finding the equaliser.
'But we have made mistakes, both in attack and on defence - and against a team like Manchester, you pay a high price for them.'
The only positive note for Roma is that captain Francesco Totti looks set to recover in time for the game in Manchester.
Totti, Roma's top scorer, missed the opening leg because of a thigh injury.
'Totti is a very important player for us,' said De Rossi. 'We hope he will be available for the return leg.'