Tottenham tore apart a woeful Southampton to win 5-2 in the Premier League on Saturday.
Harry Kane volleyed in on the turn just minutes after kick-off, but the effort was ruled out for a marginal offside in the build-up, while Danny Ings and Kane again saw further strikes disallowed.
But two brilliant goals were not denied by flags or video reviews: Danny Ings with a tremendous touch and strike on the turn to open the scoring, and Son Heung-min with a clipped finish to equalise.
After half-time it was all Spurs; straight after the restart Son again showed his finishing prowess with a great finish when put through one-on-one, then completed his hat-trick and added a fourth with two more in the space of 10 minutes, before Kane added a close-range fifth for his side and Ings netted a late penalty.
Here are five things we learned from the game at St. Mary’s.
Decision days for Dele
How far down the order of preference is Dele Alli right now at Tottenham?
He was subbed at half-time on the opening day, left out in midweek and again here at Saints, with Son, Lucas Moura, Steven Bergwijn, Erik Lamela all in the squad and the previously out-of-favour Tanguy Ndombele starting in his attacking midfield role.
All this, and Gareth Bale wasn’t even yet involved.
There are lots of games ahead and rotation will be an important aspect of the squad, but Mourinho won’t simply put him in the team just to save others’ legs - he has to still contribute to winning games and clearly the manager doesn’t feel he’s doing so at present.
Aside from selection issues, there emerged rumours during the game that PSG are keen to explore the chance of signing him. Is a new start what’s required for Dele after a disappointing last couple of seasons?
England’s No. 9…and No. 10?
For 45 minutes, this talking point was exclusively a Danny Ings appreciation section; he was utterly spectacular for Saints, a non-stop dynamo who had everything in his game from confidence and energy to a tremendous first touch and an unerring finish.
He is unquestionably in top form right now, Saints’ best player and most likely goal threat, and he must be making a huge claim to be much more regularly involved for Gareth Southgate’s England squad.
Ahead of though, of course, is Harry Kane - and in the second half it was he who stepped up massively.
In a slightly different way, though: creator-in-chief for Spurs, dropping into clever areas, finding pinpoint passes through gaps and claiming no fewer than four assists.
Start them together!
Kane might have been the creator, but it was Korean forward Son who applied the finishing touch.
His movement was relentless and unstoppable, while there are few players who can lay claim to being as ruthless and versatile as he is when it comes to one-on-one chances.
Not only is he technically gifted but he happily finishes with either foot, as he displayed here to such great effect.
Son was consistent in finding the spaces and the timing of his runs, and the service was very much present for him to keep putting the chances away.
As good as those goals were, the lack of ability to stop the same type of chance occurring again and again must be a concern for Ralph Hasenhuttl.
Saints constantly left space in behind, didn’t hold a firm defensive line and were exploited when the pass from deep was made.
Considering they had a few warning signs in the first half with the offside goals, it’s a really worry to start the season allowing eight goals in three games.
Much work lies ahead; this wasn’t as bad as a 9-0 loss perhaps but Saints need improvements at the back, fast.
Like any other Premier League team involved in League Cup action, Spurs have now played three times in the first week of the season - an intense start, but nothing overly surprising or unusual.
From this point onward though, they have a different scale to work to: Southampton, Leyton Orient, Shkendija and Newcastle, all within the space of seven days.
Mourinho has made his feelings on the situation perfectly clear, but he was also keen to be involved in Europe and will have to pick and choose his priorities to an extent.
But wining games will be the best energiser for his players and this scoreline should improve not only confidence, but expectation. With two recent arrivals to come into the team soon, the early signs are good that Spurs can be a threat again this season.