Ashley Barnes at the double as Burnley brush aside Southampton

There are reasons why Ashley Barnes has forged a reputation as the Premier League’s leading party pooper. The script suggested this would be about the striking debutants, about Jay Rodriguez’s return to his hometown club and his meeting with his old employers, about Che Adams’s rise from the depths of non-league to the heights of the top flight. Barnes either did not read it or did not heed it.

Rodriguez was confined to a cameo and, while Adams nearly scored in the second minute, it was Barnes who delivered an eight-minute double. A £450,000 bargain continues to eclipse costlier forwards and Burnley’s record Premier League scorer delivered them their biggest opening-day top-flight win since 1966 in a manner to illustrate that, if he is their resident irritant, his nuisance value should not disguise his considerable quality: these were two fine finishes. “A very effective player,” said his manager, Sean Dyche. If it sounded like damning Barnes with faint praise, Dyche added: “He doesn’t go under the radar here.”

His exploits had an importance. Burnley mustered only 12 points in the first half of last season; they are a quarter of the way to that tally already after a masterclass in efficiency. If there were times when Southampton looked the classier outfit, Burnley scored with their first three shots on target. They were unstinting in their resolve whereas Ralph Hasenhüttl was critical of his side’s capitulation. “We lost it completely,” the Southampton manager said. “We did okay for 60 minutes. Then we lost it for 12 minutes. It was not acceptable. Three-nil down, no chance to come back.”

Perhaps Southampton are yet to fully recover from their past, unable to offload expensive arrivals in misguided spending sprees and seeing one of last summer’s signings err for Burnley’s opener. When Erik Pieters hooked the ball forward, it should have been a simple header for Jannik Vestergaard, even in the swirling wind. But the £18m defender misjudged it, failed to make contact and Barnes darted in behind to make a sweeter connection with a half-volley. “A fantastic touch and finish, it was great skill,” said Dyche. “He hasn’t scored in pre-season but he didn’t look like a striker who hadn’t scored.”

It was an ill-timed error by the Dane, with the Augsburg defender Kevin Danso joining on Thursday and set to link up with his new colleagues. “It is important to have more alternatives in the defence; not only this game showed it,” said Hasenhüttl, while affording Vestergaard little support as he made himself a candidate for demotion. “I don’t know why the centre-back missed this ball,” he said.

If Pieters, a cut-price arrival from Stoke, represented one of the transfer window’s less glamorous arrivals, he offered indications he could be an astute acquisition. “Erik has laid down a real marker,” Dyche said. He set up Barnes’s second goal with a pinpoint cross that the striker met with a crisp finish.

As the floodgates opened on the dampest of days, Johann Berg Gudmundsson whipped in a third goal from an acute angle, nicking the ball from Ryan Bertrand and advancing to bend a shot beyond Angus Gunn. Dyche said it was “a great finish”, but the celebrations were put on hold for a VAR check to see if Bertrand was fouled.

He was not, but VAR had played its part before then. Adams, who had scored 116 seconds into pre-season, almost repeated the feat when hooking an early volley into the side netting, but risked a premature departure for scything down Ben Mee. He was reprieved, as Southampton had been when Chris Wood had a goal chalked off: Barnes was ruled offside by both the referee, Graham Scott, and technology before finding his strike partner. Barnes, however, was not to be denied.