The result piles more pressure on the beleaguered Portuguese boss following United's 3-2 loss to Brighton & Hove Albion last weekend, in addition to relentless reports of unrest behind the scenes at Old Trafford.
Mourinho came out fighting in his post-match press conference, though, hitting out at journalists for their perceived lack of respect at his past achievements.
The 54-year-old's parting shot was to point out that he had won more Premier League trophies than the division's other 19 managers combined.
Here, Sports Mole provides a full transcript of the heated press conference.
What was your message to the fans at the end?
"My message was the same message as the supporters, the message that the supporters gave to the players was my message, was the same. When you play the way you play, when you create what you create, when we miss the chances that we missed, when at half time everybody was frustrated but totally convinced that we were going to win the match.
"And even with the unexpected 2-0 result, the way the team kept playing until the third goal arrived, my message to the players has to be a positive message and I'm really happy, humbled by the way the supporters reacted to the boys, I think it was very much deserved, but sometimes players deserve and they don't get what they deserve, so we have to be humbled by the supporters reactions."
Are you concerned by two defeats in the first three games? Is there a worry there that your team is on the slide?
"I wouldn't be worried if at half time we were winning 3-0 and at half time the result should be 3-0, 3-1, 2-0, but we were so, so, so much the better team in the first half, I wouldn't be worried with that. Everything looked okay at half time, so what was the problem in the second half? Did you see the goal?"
Do you know what your best back-four is at the moment?
"Why not? Because in the first game [Victor] Lindelof and [Eric] Bailly, and today played [Phil] Jones and [Chris] Smalling, but now Jones is injured, and next match it will be Smalling, with another one, and when Marcos Rojo comes he will be an option, and no, I don't know my best back four."
Is it affecting them by changing them a lot? Is that affecting the confidence of the way they play?
If you play a midfielder in a back-three (Ander Herrera) does that not affect Lindelof's confidence? Suggests you don't trust him in a back-three?
"You want to make the miracle of my team played so well and strategically we were so so good and you want to try and transform this press conference into 'let's blame the guy'. You have to tell me what is the most important thing.
"When I win matches I come here many times and you are not happy that I won matches, and you say the most important thing is the way of playing."
I'm just asking about your defending...
"No, no, no, you have to make a decision in relation to that, because I need to know what is the most important thing. If it is is to play well or if it is to win matches? Is it to play offensively, or is it to play for a certain result?
"Today we were aggressive, we press high, Tottenham couldn't make two passes coming from the back, they made lots of mistakes because of our pressure high, we project the full-backs, we had Valencia and Luke Shaw arriving in dangerous positions, we miss goals with an open goal, we missed chances, we were unlucky in rebounds in both goals, we lost a game because we conceded a goal from the first corner of the match against us on minute 50-something.
"In the first-half, zero free kicks, zero corners conceded, in minute 50-something they have one corner and score a goal, and you want, with that goal, you want to transform the story of your game. But don't lose your time, because today I had the proof that the best judge in football are the supporters, they are the best judge."
But many of the supporters walked out...
"I would do the same, losing 3-0, taking two hours from here to the centre of Manchester, because it's where I live and I know that after matches it takes two hours, so I would do the same, so keep trying, keep trying, keep trying."
But are they not judging your team by walking out?
"We lost last season here against Sevilla (last season in the Champions League last 16) and we were booed, because we deserved, because we were not good, because we were not dangerous enough, because Sevilla deserved to win the match. We were booed, and deservedly.
"Today the players left the pitch after losing at home and they were applauded, because they deserved it, so keep trying, and trying, and trying, and keep trying.
"Just to finish, do you know what was the result? This [holding three fingers up]. 3-0, 3-0. Do you know what this is? 3-0. But it also means three Premierships and I won more Premierships alone than the other 19 managers together. Three for me and two for them two. So respect man, respect, respect, respect."