Having lost their opening two UEFA Champions League group stage games of the season, the clash with Kobenhavn on Tuesday evening was do or die for Manchester United.
And although it wasn't pretty, the Red Devils did eventually see off the Danish champions thanks to a second-half goal from Harry Maguire and a last-minute penalty save from Andre Onana.
Here's 90min's takeaways from that crucial win...
Harry Maguire has rediscovered his confidence and his best form
From being stripped of the Man Utd captaincy and nearly forced out of Old Trafford to being the match-winner in a Champions League game - it's fair to say that Harry Maguire's turnaround in fortunes has been rather remarkable.
Thrown back into the starting XI thanks to the myriad of injuries in defence recently - Raphael Varane, Lisandro Martinez, Luke Shaw, Tyrell Malacia, Aaron Wan-Bissaka and Sergio Reguilon have all spent time on the sidelines - Maguire has more than made the most of his opportunities.
The centre-back earned a spot in the 90min Premier League team of the week for his performance in Saturday's 2-1 win at Sheffield United, and once again shone in midweek against Kobenhavn by scoring the winning goal at Old Trafford.
Maguire looks to have re-found his mojo.
Man Utd are too reliant on Christian Eriksen
Put simply, without Christian Eriksen in the lineup during the first half, Man Utd looked utterly devoid of any semblance of creative spark.
In the second half, Eriksen was introduced and the Red Devils' offensive performance noticeably improved - Man Utd had double the efforts on goal in the second half in comparison to the first.
Due to his previous health issues and now being the wrong side of 30, Man Utd simply can't rely on Eriksen to be the sole creative force as much as they have in recent weeks.
Ten Hag will be hoping that Mason Mount's return will help his team cope a bit more without Eriksen moving forward.
Man Utd are still, fundamentally, a counter-attacking team
Bar Maguire's goal and Onana's save, the loudest Old Trafford got during the game against Kobenhavn on Tuesday night was when a brilliant sweeping counter attack almost led to an Alejandro Garnacho goal.
The young wide player would fluff his lines when played through one-on-one with Kamil Grabara by Bruno Fernandes, but the reaction from the Old Trafford crowd to the incisive bit of play said a lot about what fans actually want from this current Man Utd team: for them to play to their strengths.
Despite attempts to change how Man Utd approach games, adopting the modern style of trying to wear down teams with endless possession in and around the opposition penalty area, the fact of the matter is that the club's star players - Bruno Fernandes and Marcus Rashford - are at their best when playing on the break.
And having endured a rather horrendous start to the 2023/24 season playing a more methodical style, it might be best to just go back to those counter-attacking basics in the coming weeks in order to right the ship - especially against Manchester City at the weekend.
Ten Hag stressed in pre-season that he wants Man Utd to be the best transition team in the world anyway, but they're still well short of that goal.
Andre Onana is actually quite good
The best goalkeeper in Champions League last season is actually quite a good goalkeeper; who knew?
Andre Onana has, in truth, been pretty bad since he made a the big money move from Inter to Man Utd in the summer, but he did finally show what he's capable of on Tuesday night.
He was in stunning form against Kobenhavn, making four brilliant stops including a game-saving one to deny Jordan Larsson a last minute equaliser from the spot.
Red Devils fans will be hoping that Tuesday's performance is a sign of things to come from Onana.
Marcus Rashford's form is concerning
Coming off the back of a career best season, and having signed a bumper new contract, a lot was expected of Marcus Rashford during the 2023/24 campaign.
And, so far, not a lot has been delivered.
Despite starting all 12 of Man Utd's Premier League and Champions League games, Rashford has managed a measly one goal in all competitions and rarely looks anywhere near as threatening in the final third as he did at the tail end of last season.
With the rest of the squad also struggling in front of goal - Man Utd have scored the same amount of Premier League goals as notoriously goal shy Wolves so far this season - Rashford needs to re-find his best form; and fast.
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This article was originally published on 90min as Five takeaways from Man Utd's Champions League win over Kobenhavn.