Southampton, so often wasteful, produced a rare display of efficiency to complement their nimble play and deservedly prevail in this battle of two beleaguered sides. By coming from behind to claim a first Premier League away win since September, they climbed out of the relegation zone, eased pressure on Mauricio Pellegrino and plunged West Brom into deeper bother.

The home team took an early lead through Ahmed Hegazi but wound up soundly beaten. A smattering of boos at the final whistle suggested many locals found little consolation in the fact this was relatively entertaining fare. West Brom were again more enterprising than they had been under Tony Pulis but the result means they have won only one league match since Alan Pardew took over in November. They were a point above the relegation zone then; this defeat leaves them four adrift at the foot of the table.

With both teams in the bottom three before play began, the Hawthorns might have been gripped by tension but the atmosphere before kick-off was quite different – appreciative, almost joyful – thanks to a wonderful celebration of the life of Cyrille Regis. It was suitably warm and powerful.

After attention turned to the match, West Brom fans leapt to rejoice at Hegazi’s opening goal. The manner of it seemed ominous for Southampton, as the centre-back brushed easily past Jack Stephens in the fourth minute to head Chris Brunt’s corner into the net. The visitors had failed abysmally to defend against West Brom’s most obvious threat.

Southampton looked to be in trouble and it was not long before Pellegrino was targeted by a rendition of “you’re getting sacked in the morning”. But his team soon shut up the singers, turning the tables with two goals just before the break and a third shortly after it.

Mario Lemina, integral to most Southampton moves, struck their first goal in the 40th minute, lashing into the net from 25 yards. Three minutes later, Stephens atoned for his earlier mistake by giving Hegazi the slip at a corner and glancing James Ward-Prowse’s delivery into the net.

When Southampton were awarded a free-kick just outside the box in the 55th minute, Sofiane Boufal demanded to take it. But Ward-Prowse refused to give him the ball and the Moroccan was ushered away by team-mates. Then Ward-Prowse curled the ball beyond the West Brom wall and into the net. Point proved.

“It’s good when you are positive and want to do it,” said Pellegrino of Boufal’s attempted usurpation. “But when you’re too ambitious, it’s not too good. But all of them are young and will learn and think to do what is best for the team.”

The 3-1 scoreline reflected the play in the first hour because, once they came to terms with their rude awakening, Southampton were the better side. Yet for all their fluent play, they suffered for a while from a familiar lack of edge. Even their record signing, Guido Carrillo, fluffed a couple of early chances on his first start. Gradually Southampton grew teeth. Carrillo would have equalised from a header around the half-hour if not for an excellent one-handed save by Ben Foster.

Daniel Sturridge fired a cross-shot inches wide after a delightful through-ball by Brunt. The Liverpool loanee twinkled on his first start for West Brom but faded before being withdrawn in the 62nd minute. That was probably down to a lack of fitness and a dearth of regular service. West Brom’s long injury list was a factor in that and also, according to Pardew, in the result. “The squad was a little light today and I think that showed,” he said. “Southampton looked a little fresher.”

Pardew threw on every available attacker as West Brom went in search of a route back into contention. Brunt found one in the 72nd minute, curling a typically dangerous cross into the box for Salomón Rondón to nod home.

Shane Long, booed on his return to the club he left amid acrimony in 2014, should have restored Southampton’s two-goal cushion but headed over the bar after a cross by Cédric Soares. West Brom, however, could not muster enough quality to profit from that reprieve.