The Portuguese visitors took a shock lead in the fourth minute through Phil Jones' own goal but United equalised on the half-hour when Dimitar Berbatov - in the team in place of Wayne Rooney, who was nursing a hip problem from the Barclays Premier League win at Swansea on Saturday - headed in Nani's centre.

Darren Fletcher put the hosts in front 14 minutes after the break, only for Pablo Aimar to draw things level again seconds later, leaving Ferguson's men needing a point from their trip to Basle next month to qualify for the last 16 - and their chances of winning the group looking slim.

The Scot, though, felt his side deserved more for their efforts.

"I think we did well," Ferguson said.

"It is hard when you lose a goal straight away in a match and it took us a bit of a while to get our rhythm going again, but once we did we played really well.

"We didn't deserve what happened tonight, but football can be like that.

"If we had had just a few minutes after we had scored the second goal I think we would have been okay, but it was too early to lose that second goal."

Asked about Rooney's condition, Ferguson said: "He wasn't fit for tonight, so we need to wait to see what he is like over the next few days.

"We will give him every chance, of course - we did for today, but he wasn't really fit, so we'll just have to wait."

Benfica's second goal came when United goalkeeper David de Gea's poor clearance fell to Bruno Cesar, whose cross bounced off Rio Ferdinand and was converted from close range by Aimar.

Ferguson refused to criticise De Gea - or Jones for diverting in the opener - and was keen to praise Berbatov, who scored his first Champions League goal in three years but also missed a good late chance to make it 3-2 when he volleyed over the bar.

"The first goal was unfortunate - you don't expect that," Ferguson said.

"The ball is fired in through a ruck of players and unfortunately for young Phil it has cannoned off him. It is just one of the things that happen in football.

"With the second one, obviously David should have just put it in the terracing, but he is confident on the ball and he expresses himself always that way. I'm not blaming him in any way.

"Berbatov could have scored a hat-trick. He missed that opportunity near the end which was a bit unlucky - he could have maybe taken it down - but nonetheless, he played very well.

"We always know there is a goal in Dimitar, you always know he has the ability to turn the game and that is why we played him tonight. He is always in my thoughts."

Ferguson admitted that with Benfica - whose qualification is now confirmed - leading the group and facing a home fixture against Romanian minnows Otelul Galati in the final round of games, United appear to be playing for second place, meaning a potentially tough draw in the next round if they do progress.

But Ferguson said: "It makes it a bit harder of course, but if you look at it in a different way - maybe the bigger game will suit us anyway.

"Hopefully we are in that situation, in second place - because I don't think Benfica will lose to Galati, I'm sure they will win that match.

"Then the opportunities are against (a team like) Inter, Barcelona, Real Madrid or Bayern Munich.

"You have to judge that in this way - if you played them in the semi-final or the final, you would be only be too delighted, knowing the possibility there is to win."

Benfica coach Jorge Jesus was delighted with his players.

"It was a very exciting match," Jesus said.

"We did exceptionally well - we are used to having games like this in (Benfica's home ground) the Stadium of Light. The atmosphere was fantastic.

"We had a great game and it could have changed at any time for either team.

"The result gives us qualification to the next phase and I would like to congratulate my players - they played fantastically."