The second-half downpour reflected the wider mood at Old Trafford after Manchester United suffered another painful defeat, which once again brought manager Erik ten Hag's position under scrutiny.
Sunday's dire 3-0 loss to Tottenham, in which captain Bruno Fernandes was sent off with the hosts already trailing before half-time, left United 12th in the Premier League with just seven points from their opening six games.
The nature of the performance, particularly with 11 players still on the pitch in a disjointed first half, received heavy criticism.
Former Manchester United defender Gary Neville called the display "disgusting" and "disgraceful", while fellow Sky Sports pundit Jamie Redknapp said it was "embarrassing" and the club had hit "rock bottom".
Chris Sutton added on BBC Radio 5 Live: "That's the type of performance which gets the manager the sack."
The stats do not make for pleasant reading for Ten Hag and his players:
Manchester United's seven points are the club's joint-fewest after six games of a Premier League season.
Only in the 2007-08 season have United scored fewer goals in their first six Premier League games.
United have lost consecutive Premier League matches without scoring at Old Trafford for the first time since November 2021, in what were Ole Gunnar Solskjaer's final two home games in charge before he was sacked.
United have now lost more Premier League matches by three or more goals since Sir Alex Ferguson left the club (23 in 424 games) than they did in 1,035 league games under the Scot (22).
Ten Hag came under pressure last season but was ultimately backed by the owners following co-owner Sir Jim Ratcliffe's review of the team's performance.
United finished third in the Premier League in the Dutchman's first season and ended the club's six-year wait for silverware by winning the Carabao Cup.
Ten Hag's second season proved far more challenging as United finished eighth in the league and were knocked out of the Champions League at the group stage. That was redeemed somewhat by an FA Cup final victory over Premier League champions Manchester City that denied their neighbours a Double.
However, the start of the 2024-25 campaign has not helped inspire confidence that the club is moving in the right direction under the former Ajax boss, 54.
"I think they've got to make a big decision this week - I think his time might be up," former Premier League midfielder Robbie Savage told BBC Radio 5 Live.
Neville, speaking on Sky Sports, said: "It's one of the worst performances I have seen under Ten Hag - and that is saying something. It is really bad."
So bad, in fact, that former United player Ashley Young echoed Neville's calls for the United players to hold a "crisis meeting" this week.
"Today has shocked me about how low they have gone," added ex-United captain Neville. "That felt like one of those days where they sank really low."
Redknapp was also scathing as he added on Sky Sports: "I just don't see how he [Ten Hag] can keep his job. He looks completely lost and I don't know how he can turn it around.
"He has already had enough time. I just don't see how he is the man to take it forward - the only problem is I don't know who is, it's such a difficult job."
Former Man Utd defender Phil Jones added on BBC Match of the Day: "They are struggling for form. The pressing, they were getting there too late and were leaving massive spaces.
"A tough one to take for Man Utd. There is no player that doesn’t want to produce effort and performance. It is tough but they have to find a way.
"These players have to solve it, even if it means by discussions among themselves, but they are in a tough run and have some rough games coming up."
In a show of defiance, Ten Hag said "it is always a new day" when asked where United go from here, but admitted his side "made many mistakes" and "lost confidence" after conceding inside three minutes.
But asked if he was worried about his future following last season's uncertainty, he added: "No, I am not thinking about this. I think we all made together this decision to stay together, as an ownership, as a leadership group in the summer.
"We made the decision from a clear review what we have to improve as an organisation and how we want to construct a squad and all the decision-making is with togetherness. But we knew it will take some time.
"I think we will get better, we need some time. We are all on one page or in one boat together, the ownership, the leadership group, the staff and the players group as well. I don't have that concern."
Manchester United were already being outclassed by Tottenham long before Fernandes' controversial 42nd-minute dismissal, although it left them with a mountain to climb.
The midfielder appeared to slip as he lunged into a tackle on James Maddison and was shown a straight red card by referee Chris Kavanagh, a decision the video assistant referee (VAR) did not overturn.
Ten Hag disagreed with the outcome and claimed "the red card changed the game" as he added: "It was only 1-0. We could have made a comeback and it had a big impact on the game."
Fernandes told BBC Match of the Day: "I was the man sent off, the one that let them down. The team showed a lot of character, a lot of resilience, a lot of fight.
"[It was] never a red card, that is my view. I agree that it is a foul. If he wants to give me a yellow because they are going to go on a counter then I agree. But more than that, no.
"I have to appreciate all the effort my team-mates gave to try and return to the game but it wasn't possible. They showed great effort and character and I was happy for that."
Everton's 39-year-old full-back Young, who spent nine years at Old Trafford, said on Sky Sports: "I don't think it is serious foul play, he slips. I think the referee has got it wrong."
Jones, ex-Brighton striker Glenn Murray and former Spurs midfielder Danny Murphy agreed on Match of the Day it should not have been a red card.
But former Everton midfielder Leon Osman added on BBC Radio 5 Live: "It didn't look great. He certainly makes contact with the studs just below the knee of James Maddison. Maybe there was a slip, but that is cynical."
Tottenham began the day one place above Manchester United in 10th position, having suffered losses to Newcastle and Arsenal in their opening five games.
But Spurs produced a dominant display at Old Trafford, scoring three and recording an expected goals value of 5.33 as Ange Postecoglou's side took full advantage of United's shortcomings.
Neville said Tottenham were "outstanding" in dismantling the hosts, despite the absence of injured captain Son Heung-min.
"Tottenham have been really good and have got the scoreline their performance deserved," he added. "A really good day for Ange Postecoglou, who has had a few questions asked of him in recent weeks."
Osman said: "We spoke before the game about the significance of winning this fixture. Spurs look like they are a team who are challenging for the top four, while United look all over the place, a team which looks in disarray."
It was a fourth successive win in all competitions for Spurs, following just one win in four prior, and ensured they remain within three points of the top four in the early standings.