Erik ten Hag saw Manchester United's recent revival end with a whimper in the Europa League as Real Sociedad ground out a 1-0 win at Old Trafford.
A controversial penalty, given after a ball bounced off Lisandro Martinez's thigh into his arm, was coolly dispatched by Brais Mendez to condemn United to their first defeat in five matches.
United failed to muster up an adequate response following Mendez's 58th minute opener and managed just three shots on target to cap a disappointing night.
Here, Mirror Football looks at the winners and losers in the wake of Thursday night's surprise result...
Winners
Christian Eriksen
Manchester United may have made more eye-catching signings than Christian Eriksen this summer, but the Danish playmaker is outshining them all right now.
The former Tottenham and Brentford man has looked rejuvenated in an unfamiliar deeper role; so much so that Ten Hag decided to stick with the 30-year-old and nudge Fred into a more advanced role to lead United's press alongside Cristiano Ronaldo.
While Fred floundered, Eriksen further underlined his credentials in his new role and was central to the limited moments of promise that United produced before he was withdrawn at the break. It's likely Eriksen's half-time substitution was pre-planned - and it's hard to argue with Ten Hag's approach when you consider how important Eriksen has already become to Manchester United.
Charlie McNeill
On a pretty dour night for Manchester United, the debut of youngster Charlie McNeill was one bright spark for Ten Hag.
The centre-forward, who was on United's books as a youngster before joining Manchester City's academy in 2014, rejoined United two years ago and has been training with the senior squad in recent weeks.
And with time ticking away at Old Trafford, McNeill has handed his senior bow by Ten Hag. McNeill, who has reportedly scored more than 600 goals across United's youth team, didn't really have enough time to impact the match, but there will be plenty of other opportunities for the 18-year-old to stamp his mark for Manchester United in the future.
Losers
Cristiano Ronaldo
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Ronaldo's desire to quit the club over their failure to qualify for the Champions League indicates that he believes he is above playing in the Europa League - but his performance on Thursday night failed to back that up.
The Portuguese superstar looked his age against Real Sociedad and failed to make the most of his chance to impress Ten Hag, who has deployed Marcus Rashford as a central striker in recent weeks.
The thought of Ronaldo playing second fiddle to Rashford would have been unthinkable 12 months ago when the veteran returned to Old Trafford. But that is now the reality - and on this evidence, it's unlikely to change anytime soon.
Fred
Fred was, perhaps, one of a handful of players who emerged from a torrid campaign with any morsel of credit in the wake of his improved performances. But the Brazilian midfielder was nothing short of a liability in a move advanced role against Sociedad.
The 29-year-old failed to lead the press and struggled to have any sort of impact in the final third before he was nudged back into a deeper role after the break.
With Eriksen thriving once again as a deep-lying playmaker and Scott McTominay establishing himself as a mainstay under Ten Hag, Fred is fast becoming the odd man out at Manchester United.
Casemiro
Manchester United fans have been waiting to see Casemiro integrated into the first-team fold - but the Brazilian enforcer's debut was massively underwhelming.
Casemiro will need time to adapt to his new surroundings and an element of rust was inevitable, but the former Real Madrid superstar was not the calming influence in midfield that Manchester United sorely need.
United will be hoping in time that the Casemiro's European pedigree can rub off on a group who are desperate to get back to the Champions League.
