Harry Kane‘s goal and two from Lucas Moura condemned United to a chastening Old Trafford loss which will do little to quash rumours of unrest at Old Trafford.
But Mourinho pointedly stayed on the pitch to applaud the supporters who had sung his name towards the end of the match.
And afterwards he claimed the performance of his players proved the solidarity in the dressing room as well as in the stands.
“We worked very well during the week, we prepared well, we played well, the players had a fantastic attitude,” Mourinho told Sky Sports.
“At half-time the result should be 2-0, 3-1, 3-0, but then something changed the game a bit and the result was 2-0 but the team was in the game.
“I think everyone felt one goal could change the direction of game, Tottenham felt it, we did too, but then the third goal changed the game.
“If anyone watched this game one thing they will know for sure, the team is united.
“A team doesn’t fight like they fought if they are not united. I think it’s time to stop with the untruths.
“A team that fights the way they did with the solidarity between the players, the dignity to play together for Manchester United and lose at home, of course it’s a very difficult thing for anyone.
“I think one thing is clear, the team are united. There is no union without the manager.”
Liverpool are seen in some quarters as the only viable challengers to champions Manchester City this season, but England striker Kane was happy to big up Tottenham’s chances.
“That’s massive, to come here and win the way we did is a big statement,” he told Sky Sports.
“We wanted to start the season well and three wins out of three is a great start.
“We didn’t play well in the first half but we came in at 0-0 and said we had to step up the tempo. We got the first goal and then we punished them, Lucas with two great finishes, and we saw the game out.
“That’s the only way we’ll win the league. We haven’t started well in previous years, we’ve had to play catch-up, but the top six are so strong now you have to stay with them.
“This will give us huge belief, it’s a great statement tonight.
“We’re trying to create our own history at Spurs. We’ve not been top of the league over the years like United, like Chelsea. We’ve done well in the last few years but not quite got there – but we have the drive to take the club to the next level.”
Spurs were criticised for not adding to their squad over the summer but Kane said: “A lot of us have been playing together for a while and that helps.
“It’s a long old season and at times like today in the first half we stuck together, that’s what will help us win the title.
“The gaffer said he is not bringing players in who won’t improve the squad and that’s a big bonus for us.”
Phil Jones and Chris Smalling made their first starts of the season for Manchester United on Monday, with manager Jose Mourinho reacting to last week’s shambolic defeat to Brighton by completely changing his rearguard. Out went Eric Bailly and Victor Lindelof and in came the English duo, alongside Ander Herrera in a back three.
The change worked for a half, but United fell apart in the second half as Jones and Smalling were at fault for three Tottenham goals in a 3-0 loss.
Tackles – 2
Clearances – 5
Interceptions – 1
Blocks – 1
Aerial duels won – 6/6
Tackles – 1
Clearances – 4
Interceptions – 2
Blocks – 0
Aerial duels won – 0/0
For a while, Jones and Smalling looked an instant improvement on Bailly and Lindelof. In the first half both added stability to United’s back line, with Smalling immaculate in the air and producing a couple of key tackles. Herrera’s presence alongside them helped, as well, as they contained Spurs’ attacking threat.
However, a second-half collapse saw Jones at fault for two goals in two minutes, then taken off for an injury, before Smalling – who had a good game otherwise – was beaten for Spurs’ third.
The lack of concentration from Manchester United's centre backs (apart from Smalling tonight) has been nothing short of embarrassing. Genuinely shocking.— Liam Canning (@LiamPaulCanning) August 27, 2018
Both defenders had solid first halves, with Smalling in particular putting in some excellent tackles. He looked assured during the first 45 minutes, as did Jones, as they kept Tottenham at bay.
Spurs barely had a sniff in the first half, largely because of United’s dominance in midfield but also because Smalling and Jones were resolute whenever their opponents threatened. It made the second-half collapse all the more painful to watch.
Jones was at fault for Spurs’ first goal, losing Harry Kane and giving him just enough space to plant a perfect header into the corner. The floodgates opened from there. He was partially at fault again a minute later, caught out of position as Spurs broke, leaving his defence at sixes and sevens to allow Lucas Moura to score.
Smalling actually had a good game overall, showing application that his fellow defenders lacked, but lost a one-on-one duel for Spurs’ third.
First time MUFC have conceded seven or more goals in the opening three league games for 49 years.— Andy Mitten (@AndyMitten) August 27, 2018
A good first half can’t make up for what transpired after the break, when Jones essentially cost United the game with two mistakes in two minutes. Making it more painful was the way Smalling was beaten for Spurs’ third.
The duo knew they were expected to be an improvement on Bailly and Lindelof, and for the first 45 minutes they seemed like they were. Ultimately, however, they showed how bare United’s defensive cupboard is.
RATING – 3/10
The promise of the first half dissolved into a nightmare at Old Trafford as Manchester United were blown apart in a counterattacking masterclass by Tottenham.
United had their moments before the break, with Romelu Lukaku missing a gaping net, but their defence was obliterated through the air and on the ground in the second half against Spurs.
Below are United’s ratings – and it makes grim reading for Red Devils fans.
MANCHESTER UNITED (4-3-2-1)
David De Gea – Faultless for goals, but awkward parry from a Kane shot nearly opened the door for Moura. Should he command defence more? 6
Antonio Valencia – Gave United buckets more energy on right over Darmian. Went walkabouts for great Alli chance, though. 6
Chris Smalling – Started well, including last-ditch tackle on Dele, until he was caught 10 yards up field for second goal. Burned by Moura for third. 4
Phil Jones – Could have given way penalty with a marginal call on Moura. Lost physical battle to Kane – and for Spurs’ opener. 3
Luke Shaw – Can’t be picked on by Mourinho at the moment. Some lung-busting runs down the left and neat touches. 7
Ander Herrera – Centre-back off the ball and everywhere when United were on it. Great tackle on Alli, but soft on Moura goal. 6
Nemanja Matic – Looked rusty on return to side. Was pinched possession from in first half – and luckily it didn’t lead to goal. 5
Fred – Showed a few more glimpses of what he could become for United with effervescent display. Had a couple of decent efforts. 7
Paul Pogba – When his team needed him after the two-goal sucker-punch, didn’t rise up. Where’s the World Cup winner? 4
Jesse Lingard – Played a key role in United’s urgent vibrancy, but as ever, doubts he has world-class guile as a No10. 6
Romelu Lukaku – Four shots and no goal, including the net at his mercy after rounding Lloris. This version of United needs a clinical striker. 4
Alexis Sanchez (for Herrera, 55′) – So much effort but such little payoff. Carries impression of man trying to do too much. 5
Victor Lindelof (for Jones, 58′) – Mind melt of a back pass and then all at sea marking Kane on corner, who should have scored. 3
Marouane Fellaini (for Matic, 61′) – Thrown on to make something happen. Aside from winning a few headers, didn’t. 5