Nathan Redmond's cool finish from Jay Rodriguez's pass gave Saints a crucial lead to take to Anfield on 25 January - but Southampton can count themselves unlucky not to be in complete control of this battle for a place at Wembley.

Liverpool's much-criticised goalkeeper Loris Karius was one of very few in Jurgen Klopp's side to distinguish himself amid a shocking performance, making two fine first-half saves from goalscorer Redmond.

Karius's one-handed save from Redmond right on half-time was vital but he was helpless late on as the same player threatened once more, Liverpool enjoying more good fortune as his effort came back off the bar.
 

Saints satisfied - but is there disappointment too?

Southampton's recent form has been indifferent but manager Claude Puel will have been delighted with their display at St Mary's.

After a brief early spell of Liverpool pressure, when Roberto Firmino tested Fraser Forster, Southampton were completely untroubled throughout an impressive performance.

Saints were sharp in the tackle, more assured in possession and a continual threat through Redmond and the industrious Rodriguez.

They will be left, however, with a tinge of regret despite an excellent, fully merited result that gives them real reason for optimism for the second leg at Anfield.

Karius and the woodwork kept them at bay and they had many other opportunities to produce a scoreline reflecting their superiority.

Southampton could have slammed the door on Liverpool - instead it remains ajar.

Karius spares lucky Liverpool

Karius has had to undergo a severe examination of his goalkeeping credentials and endure heavy public criticism in the early months of his Liverpool career.

Klopp placed great faith in the 23-year-old German, signed from his former club Mainz in a £4.75m deal this summer - eventually choosing him ahead of established first-choice Simon Mignolet.

The decision backfired and he was forced to drop Karius after two poor, error-strewn performances in the 4-3 loss at Bournemouth and the 2-2 home draw with West Ham.

Klopp has never lost belief, however, choosing Karius as his cup keeper - and he was rewarded here with an outstanding display, especially with two excellent saves from Redmond.

He is responsible for Liverpool still being in this tie after a shocking display.

Man of the match: Virgil van Dijk (Southampton)

What the managers said

Southampton manager Claude Puel:

"Liverpool had just the one chance all game. We were unlucky at the end because we know Liverpool away in the second leg will be very difficult.

"This competition is exciting, now it is important to keep the good concentration for the Premier League.

"We lost three games so it is important to have a good reaction."

Liverpool boss Jurgen Klopp:

"We needed Loris Karius to save our lives two or three times.

"The best thing for us is the result. We know that we can play better at Anfield - nothing is decided.

"We cannot be happy with the performance, Southampton cannot be happy with the result. It could and should have been 2-0, 3-0."
Puel in the black against Reds - the key stats

    After losing four of their previous five matches against Liverpool (D1), Southampton are now unbeaten in their past three versus the Reds (W2 D1).
    Claude Puel is unbeaten in four clashes with Liverpool as manager (W2 D2).
    Liverpool have managed only two shots on target in both of their meetings with Southampton this season - only against Man City (one) have they registered fewer in a match this term.
    Jay Rodriguez provided his first assist in all competitions for Southampton since January 2014 against Arsenal.
    Southampton have kept more clean sheets than any other team in the EFL Cup this season (four).

'An opportunity missed'

Former Leicester and Birmingham striker Steve Claridge:

You can make a strong case for Southampton winning 2-0 or even 3-0. Everyone here is happy but this is an opportunity missed.

If Southampton don't go through they will be kicking themselves.