Newcastle’s success over Arsenal on Wednesday night will no doubt have encouraged Spurs, who faced a similar task in holding onto their 1-0 first-leg advantage.
Liverpool were at them from the start, but with four clean sheets from their last eight matches and new signing Kevin Danso making his debut at the back, Spurs’ defence didn’t initially look like pushovers.
There were simple saves for Antonín Kinský to make from efforts by Mohamed Salah and Darwin Núñez, while Dominik Szoboszlai was caught offside in the process of netting at the near post.
Spurs had their own moments on the counter, but the tie was reset to level on 34 minutes when Salah’s outside-of-the-boot delivery bounced all the way past Núñez to Cody Gakpo, who punted it into the near bottom corner.
Liverpool looked relentless after that in the half, and would have taken the lead in the tie if Kinský hadn’t acrobatically tipped Salah’s volley onto the crossbar on the stroke of HT.
That pressure continued as soon as Liverpool kicked off again, and the Reds got their second from the spot after Núñez touched it beyond Kinský and was subsequently taken down in the area.
Salah dispatched confidently into the top left, and the home side remained in full control after that.
They soon hit the woodwork twice, with Kinský’s fingertips touching Gakpo’s drive onto the post, before Ryan Gravenberch’s long-range effort bounced directly against the left upright.
Those chances were merely a warning, and Conor Bradley next slid through Szoboszlai, who simply slotted into the bottom right.
Son Heung-min then struck the bar in Spurs’ first real chance of the match, but the Lilywhites’ misery was compounded as Virgil van Dijk out-jumped Danso to head in a fourth from Alexis Mac Allister’s corner delivery.
The record 10-time winners of this competition will now head to the capital in March to try to lift consecutive League Cups for the first time since they won four in a row in the early 1980s.
For Spurs, Ange Postecoglou will know that his tenure will likely be on thin ice come the end of the campaign unless he can guide them deep into both the FA Cup and UEFA Europa League.