They might not have kept a clean sheet, but it is hard to recall a better defensive performance from Saints this season.

Ronald Koeman's side restricted Chelsea – the Premier League’s leaders and top scorers – to just one shot on target all afternoon.

That the Blues scored from that effort should not diminish how impressive an accomplishment that is.

Chelsea had netted 40 times in 18 league games coming into this contest, yet for all their pressure – and there was certainly plenty of it, especially after half-time – they rarely opened up Saints.

Once again, Ronald Koeman proved extremely shrewd with how he set his team up.

With the loss of his first-choice full-backs – Nathaniel Clyne’s foot injury ruling him out, along with Ryan Bertrand, who was ineligible against his parent club – Koeman switched to a flat back four.

The system of three at the back had served Saints well in the last two games, but they were always likely to be in need of greater numbers in midfield against a Chelsea side that dominate possession, and the absence of Clyne and Bertrand would have made it hard to go with it again anyway.

The loss of Clyne left Koeman with a particular problem.

Toby Alderweireld represented a natural option to fill-in for him, but that would have meant removing him from the duties of marking his former Atletico Madrid teammate Diego Costa.

Koeman instead opted to play Maya Yoshida at right-back, moving Steven Davis in front of him in midfield for some additional protection, while continuing to play Sadio Mane in an advanced central position, after he was so effective there against Crystal Palace.

So much of it paid off.

Mane was a huge threat in the first half, bursting through to give Saints the lead after excellent play between Graziano Pelle and the returning Dusan Tadic.

Alderweireld was an immense presence at the heart of defence, alongside the towering Jose Fonte, and it is hard to imagine anyone keeping Diego Costa as quiet as those two did.

Matt Targett was excellent on his full Premier League debut at left-back, in what was about as tough a test as you could imagine, and although Yoshida was a bit exposed for Eden Hazard's equaliser, the Chelsea midfielder is one of the finest creative talents you will find in the game.

As brilliant as he and Cesc Fabregas were at times, Saints did well at largely negating their end product, bar that one instance.

For all of Chelsea’s domination after the break, they could find no way through, as the Saints manager and his team produced another impressive performance.