Nemanja Matic enjoyed a winning debut as Manchester United wrapped up pre-season preparations with a 2-1 victory over Sampdoria in Dublin on Thursday (AEST).

Juan Mata scored a later winner to ensure United will enter next Wednesday's (AEST) UEFA Super Cup clash against Real Madrid on a winning note, after Henrikh Mkhitaryan's header had been cancelled out by Dennis Praet.

Matic, who completed a £40 million ($66.3 million) move from Chelsea on Monday, started at the base of midfield and looked comfortable throughout his 45 minutes.

The Serbian's composure helped the UEFA Europa League winner maintain control throughout the opening period, but a series of half-time changes stifled its momentum.

Belgian midfielder Praet equalised for the Serie A side just after the hour, leaving Mata to assume the role of match-winner for Jose Mourinho's side inside the final 10 minutes.