The two sides could not be separated in the first leg of their last-16 showdown, with a 1-1 draw played out at Santiago Bernabeu.
United will feel that an away goal hands them a slight advantage heading into the return tie, but Real have shown over recent weeks that they are more than capable of finding the target at Old Trafford.
The reigning Spanish champions will arrive in England buoyed by back-to-back victories over arch-rivals Barcelona, and Benzema is confident Real can strike the right balance between risk and reward when they go in search of continental progress.
"We are going there with great confidence after beating Barcelona twice in a week," said the France international.
"We know it will be difficult for us because Manchester United are also in great form.
"It will be a great game because we have to score there. It will be a great tactical battle and we will have to take a bit of a risk. The first goal will be crucial."
Real playmaker Kaka is also looking forward to facing a European challenge head on, with the Brazilian desperate to be involved at the Theatre of Dreams.
He said: "We could have won at the Santiago Bernabeu, but it didn't happen. Now the team are confident that we can win at Old Trafford,
"The stadium is fantastic, as is the atmosphere and the fans. Any player would like to play in a match this big, so we have the belief that we can make it through this round."