Zlatan Ibrahimovic scored four minutes into his debut as Manchester United beat Galatasaray 5-2 in Sweden.
Ibrahimovic opened the scoring with a scissor kick which bounced before heading into the corner.
Jose Mourinho picked a strong starting XI, with only Chris Smalling and Mateo Darmian to return to his probably first-choice XI.
However, United were behind by half-time, with goals from Sinan Gümüş and Bruma putting the Turkish side into a 2-1 lead.
United ran riot after the break, with Wayne Rooney scoring the second and third goals, his second from the penalty spot after fine work from Marcus Rashford.
Marouane Fellaini added a fourth with a looping header, before Juan Mata sealed the victory.