Paul Pogba scored two first-half goals as Manchester United spoiled Young Boys' first appearance in the group stage of the Champions League by cruising to a comfortable 3-0 victory at the Stade de Suisse on Wednesday.
Anthony Martial also scored for United, the three-time winners who were knocked out of the competition last season in the round of 16.
Young Boys, the Swiss Super League champions, spent much of the first 20 minutes in attack, with Mohamed Ali Camara letting go of a shot from 30 yards in the 16th minute that United goalkeeper David De Gea was forced to tip over the crossbar.
Christian Fassnacht had two opportunities to put Young Boys ahead early -- one in the 30th minute, when he scuffed his shot after debutant Diogo Dalot fell down, and one in the 33rd, when De Gea punched his attempt from 24 yards over the bar -- before Pogba struck.
The midfielder, who entered with two Champions League goals in his 37 career appearances, scored his first in the competition for United in the 35th minute.
He played a quick give-and-go with Fred on the edge of the area and, after switching to his left foot under pressure from Camara, he let go with a screamer toward the near post that Young Boys keeper David Von Ballmoos could not stop.
Pogba then doubled the lead just before half-time, scoring from a penalty in the 44th minute after Luke Shaw's shot hit Young Boys' Kevin Mbabu in the right hand, which was pinned to his side.
Martial extended the lead in the 66th minute, with Pogba setting him up on the left wing for the easy finish to the counter-attack, and Romelu Lukaku nearly made it four in the 93rd minute but was ruled offside.
Young Boys nearly pulled one back in the 73rd minute when Camara's header from a corner glanced off the near post, but they never recovered and fell to their first defeat in 10 games this season.