The Red Devils played more than an hour without registering a single shot to compound a forgettable afternoon for the club in Bern
Even with Cristiano Ronaldo in fine form, Manchester United's lack of firepower was badly exposed on Tuesday as they went down to a shock 2-1 defeat at the hands of Young Boys.
It looked set to be a fine Champions League afternoon for the Red Devils when their new signing pushed them ahead after just 13 minutes.
But their Swiss hosts were barely troubled after that rocky start and recovered to record a memorable win in the group stage opener.
Young Boys goalkeeper David von Ballmoos must have feared the worst after Ronaldo's early strike, marking his return to Champions League action with United in style after more than 12 years.
But the shot-stopper instead enjoyed a relatively peaceful afternoon as United were frustrated in Bern.
That Ronaldo goal and a second effort on target 10 minutes later were the only shots of any type that the visitors mustered in the entire game.
The Reds were forced to regroup following Aaron Wan-Bissaka's red card while still in the first half, eventually pulling off Jadon Sancho, Ronaldo, Donny van de Beek and Bruno Fernandes in their attempt to sacrifice strike-power for stability at the back, and they paid dearly as Nicolas Ngamaleu and Jordan Siebatcheu netted to turn the game on its head.
Never before in the Champions League had United managed so few shots in a match, and it contributed to another forgettable match for manager Ole Gunnar Solskjaer.
Solskjaer helped United to second last season in the Premier League behind Manchester City, but he has often found continental competition a more difficult prospect.
13% - Manchester United have lost seven of their 11 UEFA Champions League matches under Ole Gunnar Solskjær. 13% of their total defeats in the competition have come under Solskjær (7/54), despite the Norwegian only being in charge for 4.8% of their matches (11/231). Fall. pic.twitter.com/5e49OVY63B
Tuesday's defeat to Young Boys was his seventh in 11 Champions League matches at the United helm, having lost three of their group stage matches last time round to finish third and settle for a place in the Europa League knock-out phase.
The manager and the Reds will hope for better fortunes in their next outing in the competition on September 29, when they welcome Villarreal - who downed Solskjaer's charges in the Europa League final last term - to Old Trafford.