The Portuguese winger played a part in both legs of this season's Champions League quarter-final tie as Sir Alex Ferguson's side followed up their 1-0 victory at Stamford Bridge by winning the return leg 2-1.
We've got the edge: Nani believes United will beat Chelsea in Sunday's crucial Premier League showdown
And United go in Sunday's home showdown on a high after clinching a place in the final at Wembley where they will meet Barcelona following their demolition of Schalke.
Nani now wants the team to continue their good work after the 6-1 aggregate victory over the Bundesliga side and end Chelsea's hopes of retaining the title. United are three points in front with three games remaining and have taken 49 points out of a possible 51 at home this season.
Nani said: 'The most important game now is Chelsea not Barcelona. It will be very difficult. But we are at home and we have had good experiences against them.
Head-to-head: United will square up to Chelsea at Old Trafford to decide where the title ends up this season
'We know if we want to win the game we have to play with confidence. The results against them in the Champions League were very good. I think that gives us the psychological advantage.
'We just have to concentrate on our football and winning the game. If we do that then everything will be fine.
'If we win this one then it is a great advantage for us. It is nearly over then. We have a great chance.'
We've done it again: Fergie celebrates as United book a place in their third Champions League final in four years
United are aiming to take Europe's top club prize for a fourth time after first winning the trophy at Wembley in 1968 when they defeated Benfica.
Nani added: 'It is very important to be all together. It would another fantastic story for this club if we win at Wembley.'
Wayne Rooney and Patrice Evra are expected to be fit to face Chelsea. Rooney missed training on Tuesday after reporting for duty with a tight hamstring and was not named on the bench against Schalke.
Back in the frame: Rooney, who was rested for the game against Schalke, is set to start against the Blues on Sunday
Evra was introduced as a second-half substitute then took a knock but shook it off as he was about to be replaced.
United manager Ferguson will ring the changes and is almost certain to revert to his first choice central-defensive partnership of Rio Ferdinand and Nemanja Vidic.
Friday Five: Classic clashes between Sir Alex Ferguson and Carlo Ancelotti This time it's for real! Chelsea and Man United gear up for title deciderMan United fans 'disgusted' at huge cost of Champions League final ticketsMan United v Chelsea: What the Premier League managers sayManchester United stars out for a pizza the action after booking reservation in Champions League finalManchester United FC news, features and opinion Chelsea FC news, features and opinion Explore more:People: Wayne Rooney, Alex Ferguson, Rio Ferdinand, Patrice Evra, Nemanja Vidic, Nani Places: Barcelona, Europe