The Tottenham boss has come under pressure of late following back-to-back losses to Newcastle and Manchester City - the latter a 6-0 defeat - and is keen to reverse their fortunes
The Portuguese has come under pressure of late after Spurs' slump in form, which culminated in a disastrous 6-0 Premier League loss to Manchester City last weekend.
However, a strong side travelled to Tromso on Thursday to grind out a 2-0 win to confirm Tottenham's top spot in Group K, putting Villas-Boas in a positive frame of mind ahead of the visit of in-form United to White Hart Lane.
"Obviously the opponent we have on Sunday is the biggest that we can have," the former Porto coach told reporters.
"But to prepare for that game, it was important to get back to winning ways and we did it in a fashion where we looked solid and created lots of chances.
"I am extremely happy with the performance and result."