Much more of this and it will become the fashion to change manager every few months. Blackburn, on the back of six successive defeats, benefited yesterday from what has become known as the “Harry Redknapp Effect”, winning their first match under Sam Allardyce by a margin they can only have dreamed of.

Like Redknapp at Tottenham, the man universally known as “Big Sam” has immediately galvanised a team previously on the slide, Rovers having all three points sewn up before the game was half an hour old.

Stoke must have known it wasn’t to be their day even before the start, when their goalkeeper, Thomas Sorensen, injured a hand during the warm-up and had to give way to Steve Simonsen. The poor deputy had to pick the ball out of the back of his net three times in the first 27 minutes, and that was that. Game over. Change your manager, change your luck.

It would be a nice story to report that Allardyce tactically worked the oracle. Nice, but untrue. In reality, Stoke gifted Rovers all three goals, leaving themselves with no prospect of recording their first away win of the season in the Premier League.

Allardyce was without his principal scorer, Roque Santa Cruz, who cried off with ankle trouble, but it is doubtful whether the Paraguayan would have been picked anyway after giving an interview on the eve of the match in which he invited “bigger” clubs to come in to buy him during the January transfer window.

Clearly disaffected, he is unlikely to last long under one of the game’s toughest task-masters. The probability is that Allardyce will sell him and use the funds raised to recruit players more committed to the cause.

Allardyce said: “Will Santa Cruz saying that affect my night out tonight? No. Is it going to bother me tomorrow? Yes. There is an issue there and it’s something I’m going to deal with very quickly.”

Matt Derbyshire, who has five goals this season, was also left out here, the new manager preferring Jason Roberts and Benni McCarthy as a strike partnership. The pair rewarded him by rattling in those three early goals.

It is 42 years since Blackburn lost seven on the trot in the league, and the board sacked Paul Ince in the belief that history was about to repeat itself. As it turned out, there was never any chance of that happening. That much was clear as early as the seventh minute, when Ibrahima Sonko needlessly gave away an obvious penalty by scything down Morten Gamst Pedersen just inside the 18-yard line as he cut in from the left. Referee Peter Walton had no hesitation in awarding the penalty and there were few protests from the Stoke players.

McCarthy made short work of his duty from the spot, tucking the ball safely inside Simonsen’s right-hand post, and the Allardyce era at Ewood Park was up and running. If Stoke thought they could retrieve a one-goal lead against such lowly opponents, they were quickly disabused. Ten minutes later it was 2-0 when Ryan Shawcross, moving to cut out Brett Emerton’s centre from the right, succeeded only in stunning the ball for Roberts, who could barely believe his fortune and grate-fully sidefooted it home from six yards.

Stoke had presented Rovers with two goals, so why stop there? After 27 minutes Sonko failed to react to a neat one-two between Roberts and McCarthy, who finished decisively from near the penalty spot, leaving Tony Pulis, the Stoke manager, apoplectic. Afterwards he was still aghast. “Christmas came early for Sam today,” he said. “Our defending was very poor. Individual mistakes cost us the game. The first goal was just diabolical. That first 26 minutes left me scratching my head. We were taking the game to them, with four corners in the first 10 minutes, we had all the play.We need people that are going to stand up and we need concentration levels far better than what we showed.”

The fans from the Potteries, who had travelled in good numbers, and had chorused their anthem, Delilah, with impressive volume, fell silent, unable to believe what was going on. Their Father Christmas outfits were distinctly bedraggled as the rain poured on their parade, literally as well as metaphorically.