Liverpool climbed back up to third in the Premier League with a 2-0 victory at Saints that left Mauricio Pellegrino under renewed pressure and his team at increasing risk of relegation.

The home supporters again turned on their manager after their latest defeat, secured by goals from Roberto Firmino and Mohamed Salah, left them in 18th place and took their visitors back above Tottenham.

It also ensured a victorious return to St Mary's for Virgil van Dijk, the £75million defender who left for Liverpool at the end of December and who so many believe disrupted and undermined Southampton's disappointing season.

The pressure on the hosts had increased with earlier, unexpected victories for Newcastle and Huddersfield, respectively over Manchester United and Bournemouth, that took them back into the bottom three.

They had had little time to settle when in only the sixth minute their afternoon worsened when they fell behind following another of Liverpool's swift breaks.

After Loris Karius threw possession out to Alex Oxlade-Chamberlain, the one-time Southampton winger curled a ball towards Salah that was missed by the clumsy Wesley Hoedt, leaving Salah with a simple pass to Firmino who from in front of goal struck first-time beyond Alex McCarthy and into the bottom right corner.

Owing largely to the vision of James Ward-Prowse, the hosts responded and threatened until Liverpool doubled their lead. The midfielder curled a fine ball over the top of Liverpool's defence and to Pierre-Emile Hojbjerg, who at the back post hesitated, allowing Karius to spread himself and then comfortably save the shot he eventually produced.

Another cross from Ward-Prowse gave club-record signing Guido Carrillo a header from in front of goal that he nodded downwards to present Karius with a routine save, and then the midfielder tested the goalkeeper with a header of his own.

Meeting Dusan Tadic's left-wing cross at the back post he forced the diving Karius to tip over the crossbar, and as on so many other occasions this season, Southampton's profligacy was then punished.

From a seemingly-unthreatening position, Joel Matip found Salah, who towards the edge of the area then ruthlessly exchanged a delightful one-two with Firmino, whose backheel into his path in front of goal was classily sent towards the bottom left corner by the Egyptian for his 29th goal of the season.

Another former Southampton player almost inspired Liverpool to a third goal midway through the second half. Sadio Mane intercepted a ball from Hojbjerg before carrying possession into the penalty area and passing to Firmino, whose low shot was saved by McCarthy but only to Salah, who then struck first-time but into the side netting.

Mane then also struck harmlessly wide, despite time and space, following a through-ball from Firmino during a period in which the hosts offered little resistance and were fortunate not to concede again.

When Pellegrino replaced Ward-Prowse with Shane Long in his pursuit of a reaction, Southampton's supporters again chanted “You don't know what you're doing”. They then booed their team at the final whistle when their defeat was confirmed.