Newcastle United skipper Bruno Guimaraes left the field looking like a man whose performance had dipped on the South Coast.

But if anything, the moment showed just how high the standards at United are right now. Bruno had an average game but still wanted to bring more to the table before Eddie Howe took him off to bring on fresh legs.

As Bruno left the field, Howe showed support to the Brazil midfielder while the subs bench - to a man - offered a high five. On a day in which Newcastle had rediscovered their fighting spirit and bounced back from the defeat to AFC Bournemouth, there was more evidence they are up for the fight as far as the Champions League are concerned.

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If Bruno was as disappointed as his expression suggested, he can console himself by the fact he'd skippered his side to another away win. The game also saw Miguel Almiron sent on as a late sub in what many believe could be his final game for the club.

Whether Howe's gesture to shove Almiron towards the fan to milk the applause may prove to be the last we see of the South American remains to be seen.

Bruno started well enough and tried to set Joelinton free in the second minute but he failed to read the pass properly with James Bree getting across to concede the corner. Despite successive corners, Newcastle could not snatch what would have been a very early lead.

Joelinton was then presented with another decent opportunity after being slipped in from the right but he blazed it over and wasted the chance. The Saints took until the 10th minute to enter the Newcastle penalty area, but when they did, they made no mistake.

The goal came after Kyle Walker-Peters made it to the byline before dragging Dan Burn with him and out of his comfort zone in the centre.

Then in Southampton's first attack, Bree clipped in a fine cross from the right and with Burn out of position and Fabian Schar rooted to the spot, it was Jan Bednarek who rose high to power home a header past Martin Dubravka.

After squandering some early openings, Newcastle looked shell-shocked and followed up with another effort three minutes later as Adam Armstrong broke down the left and then hammered a shot at Dubravka.

On 21 minutes, Mateus Fernandes lunged into Tino Livramento and picked up a yellow card. Moments later, Newcastle were handed an open invitation back into the contest.

Although, at first referee Sam Barrott wasn't convinced that Joe Aribo had made enough contact on Alexander Isak as he drifted into the box. After examining a TV replay it was clear and with Barrott urged by VAR chief for the game Chris Kavanagh to check it out, he soon pointed to the spot.

Isak stepped up calmly and sent the ball low to the left of the net to score his 18th of the season. Things would get better on the half-hour mark after Jacob Murphy's defence splitting pass found Isak before he skipped past his marker and dinked the ball off the post to make it 2-1.

The ball had been pumped up the pitch by McCarthy, and Burn won a header to find Sandro Tonali. The Italian gently couched the ball in the direction of Murphy who delicately nudged it past Aribo before piercing the home defence to set up Isak.

Joelinton thought he'd grabbed one himself on 32 minutes but the ball slammed against the post and the home side survived another close shave.

Isak then got in again on 34 minutes, but McCarthy made a stop with his legs, and suddenly Southampton looked like the team who are hot favourites to go down. Newcastle went in at the break 2-1 and were good value for their lead on the South Coast.

After some early second half pressure from the Saints, with Dubravka making a stop to deny Taylor Harwood-Bellis, Newcastle extended their advantage on 51 minutes. The goal unfolded after Schar's long ball up the pitch which was half-cleared by the Saints.

But Tonali won the second ball before Isak chested the ball to Gordon and the Scouser cushioned it into the path of Tonali. The ex-AC Milan ace then gained possession 40 yards from goal before racing through and sliding it past McCarthy to make it 3-1.

Murphy thought he'd found the net on 56 minutes but his long range effort cannoned off the post and bounced to safety. The Magpies poured forward again on 64 minutes as Isak played in Gordon who found Joelinton but his effort was deflected wide.

Southampton thought they'd pulled one back when Fernandes latched on to a long ball to beat Dubravka but a VAR call chalked it off. That resulted in the eruption of the home fans who belted out: "It's not football any more."

The Magpies made changes for the final 14 minutes with Joe Willock and Lewis Miley replacing and Miguel Almiron coming on for Gordon. Almiron twisted into the box in stoppage time to force McCarthy into a save for a moment that would have raised the roof in the away end.

Livramento then sent one just wide of the post as Newcastle looked to add gloss to the scoreline at St Mary's. Newcastle climbed back in the top four but may not stay there long with Chelsea facing Man City tonight.

Referee: Sam Barrott

Attendance: 31,141