Jose Mourinho's men were looking to build on their solid victory at Benfica on Wednesday when they travelled to Huddersfield Town on Saturday afternoon.
However, lots of things went wrong for United as they lost 2-1 to the newly-promoted outfit and surrendered their unbeaten 2017-18 record in the process.
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At 0-0, Phil Jones was forced off through injury, and his replacement, Victor Lindelof, made a big mistake which led to Laurent Depoitre doubling Huddersfield's advantage.
Despite the negatives from the match, David de Gea did little wrong, and the goalkeeper did provide one moment which Man United fans will certainly appreciate.
De Gea is United's best
With Paul Pogba and Zlatan Ibrahimovic currently injured, David de Gea comfortably stands alone in many people's eyes as Man Utd's best player.
His stunning reaction save from Joel Matip last weekend earned his side a point at Anfield, but it was his technical footballing qualities that were on show at The John Smith's Stadium.
De Gea pulls off classy skill
In the 32nd-minute of the game, Depoitre closed De Gea down as the Spanish 'keeper tried to get the ball under control inside his six-yard box.
United were 1-0 down at this point and under pressure from the hosts, that didn't stop their number one from keeping his calm in remarkable fashion to produce a lovely piece of skill.
As you can see below, De Gea was coolness personified as he flicked the ball over Depoitre, even producing some fancy footwork after bringing it down before finding Lindelof.
That said, the 26-year-old did get away with some nervy moments late on as Man Utd pushed for an equaliser following Marcus Rashford's goal, and he'll be angry at his failure to keep another clean sheet.
However, with pieces of magic like the one above, as well as his shot-stopping ability, it's easy to see why the Ballon d'or nominee is regarded by many as the very best in the world.
Do YOU think De Gea is now the best 'keeper in world football? Leave YOUR opinion in the comments box below!