Tottenham edged past Manchester City, with two first half goals from Timo Werner and Pape Matar Sarr.
This win was much needed for Spurs, after yet another disappointing away performance against Crystal Palace on Sunday.
It was not just the result that provided promise for supporters, but multiple elements of the performance that showed the Lilywhites' season is far from over.
Kulusevski's quality shines through
Dejan Kulusevski is having an outstanding campaign thus far, picking up another two assists last night.
Creating chances was only one part of what Kulusevski brought to the table against City, with tireless running off the ball, deep understanding of how Ange Postecoglou wants him to play and immense composure on the ball.
This was proved by the Swede not being dispossessed once during the match, of which he played the duration.
Kulusevski has more often than not provided the answer for Tottenham, being the creative spark that continues to light up the pitch.
With impressive upper body strength, ball-carrying ability and willingness to do the under-appreciated running in hard-fought contests, the 24-year-old is without a doubt Tottenham's player of the season so far.
Werner is capable of delivering in the final third
Timo Werner has been the centre of attention, for the wrong reasons, surrounding many supporters' quibbles about their lack of ruthlessness in the final third.
A tidy finish, past compatriot Stefan Ortega, is the confidence boost the German has been looking for.
This is not to say he is the perfect winger and takes every chance he gets with ease, even Son Heung-min squanders opportunities from time to time.
The chances that fell to the 28-year-old early in the second half is more accustomed to what fans' expectations are of the former Chelsea man.
However, Timo Werner is very useful to Ange Postecoglou, with his pace capable of taking him to a crossing position, a core element of what the Australian manager looks for in his wide players.
To find a winger with electric pace, Champions League winning experience and ability to beat a man is rare. Therefore, Werner could be key for Spurs as they go deeper into cup competitions.
Richarlison's experience proves useful
With 20 minutes left to play, the north London side were holding a one goal lead when Postecoglou chose to bring on Brazilian forward Richarlison.
This may not seem like a conventional substitution when looking to see out a win, but two key factors made it exactly what Spurs needed.
Firstly, the 27-year-old has vast experience in holding up play and letting his side regain their shape, providing them with the best chance of defending their advantage.
The ball would fall to Richarlison on the left wing and he would wait for the perfect moment to beat a man in order to win a foul.
As well as this, the striker contributes to goals, which is how Ange Postecoglou wants his team to see out results, instead of opting for defensive rigidity.
The Brazilian created a chance for himself late on, but failed to capitalise on Josko Gvardiol's misplaced throw, with Richarlison firing it straight at the keeper.
This combination of game management and attacking threat could be just what Spurs have been missing this season, with Richarlison's return from injury being just what the Lilywhites need.
Winning mentality exists within Tottenham's ranks
With a disappointing defeat to Crystal Palace, among others, this season has been full of bumps in the road for Ange Postecoglou's Tottenham.
It has often been like a box of chocolates, to quote Forest Gump, you never know what you're going to get.
This victory against an albeit weakened Man City proved that Spurs do possess a determined winning mentality.
The issue for Postecoglou is making sure that is on show every week, keeping players' motivation high.
Despite similar issues coming to the fore, such as frailty from set pieces, the collective defensive effort demonstrated this positive mindset that exists within the ranks at N17.
From Dominic Solanke's endless running to Yves Bissouma's goal line clearance, the north London side deserved to progress in the Carabao Cup.
With the contrasting matches over the last week, the players within the squad will be developing mental qualities that are required for success.
Giving Postecoglou and his squad time for this development is what Spurs' most likely route to silverware in the near future will be.