At the final whistle the contrast in emotions could not be starker. In the away end a black-and-yellow blanket of Watford supporters, basking in the low sun as well as a third successive league win, chanted Nigel Pearson’s name after watching his side, revitalised since his appointment five weeks ago, dismantle Bournemouth to leap outside the relegation zone for the first time this season. Filippo Giraldi, the Watford technical director, embraced each player pitchside, congratulating them on a stirring and punchy performance as Bournemouth stomached a ninth defeat in 11 league matches.

It is impossible to ignore Watford’s extraordinary transformation under Pearson, who has galvanised a squad short of belief in double-quick time, accumulating 13 points from six league matches. Bournemouth, meanwhile, have acquired a miserly four from the past 33 available.

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It was the substitute Roberto Pereyra who put Bournemouth out of their misery in second-half stoppage time, by which point Watford had long since sapped the life out of the hosts, draining Eddie Howe’s side of the kind of confidence and stride that Pearson has instilled seemingly overnight. Bournemouth’s belief, as Howe acknowledged, was shot by Abdoulaye Doucouré’s strike three minutes before the interval but they were short of urgency throughout, while Watford, masterfully led and spearheaded by their tenacious captain, Troy Deeney, seemed almost superhuman as they strutted around.

“Confidence is such an important thing to any team and it just felt it was lacking from that goal onwards, it seemed to dent us,” Howe said. “That’s been chipped away at and that’s my biggest challenge, to refind that. We can only regroup, learn from what we’ve delivered, analyse the game properly and improve. We need to rediscover our belief in the team, for me that’s the only thing missing because we’ve got good players. With the run we’ve been on, it’s damaged us a little bit and I think that’s the big challenge we face. I don’t doubt the players’ quality because they’ve proved and delivered it before.”

Facebook Twitter Pinterest Troy Deeney was superb in leading the line for Watford. Photograph: Richard Heathcote/Getty Images

Watford supporters serenaded a boisterous performance from start to finish but Pearson was reluctant to overindulge in a victory, which extends their unbeaten run to five matches. “It’s not a season-changing result but it is an important one, especially in the context of our own situation,” Pearson said. “There are so many games left I think it would be foolish to think that just because we have got out of the bottom three that the job is done. There is an awful long way to go. But it quantifies the work the players have put in.”

Pearson played down the magnitude of this match, but Howe described this encounter as the start of a season-defining period, with their next three matches against Norwich, Brighton and Aston Villa, all of whom are endangered at the foot of the table. Bournemouth failed to hurt Watford, who seized on a poor clearance by Mark Travers to open the scoring through Doucouré. A second goal had been a long time in the making but arrived after the hour mark when Deeney applied the finishing touch inside the box, unceremoniously thumping in after brilliant work by Ismaïla Sarr.

Travers, making his third league start in the absence of Aaron Ramsdale, apologised for his error but, in truth, Bournemouth never got going; their only shot on target came in the ninth minute when Harry Wilson’s free-kick forced Ben Foster into a relatively comfortable save. Meanwhile, Ramsdale, who was absent with a minor hamstring injury, was stationed in the Steve Fletcher Stand, doing his best to gee up supporters but there was little to stimulate the home crowd. A once free-scoring Bournemouth have gone eerily cold in attack – they have conceded nine goals without reply in their last three matches – and for Dominic Solanke the barren runs goes on, with this another fruitless league appearance, his 28th without finding the net.

Sarr was disappointed to be withdrawn eight minutes from time, with Pearson quick to pacify the winger but, in reality, the damage had already been done. Everything seemed to click for Watford, even down to Pearson’s game management, notably his trio of late changes, which were agonising from Bournemouth’s point of view. The visitors siphoned each last trickle of vim out of the hosts, powerless as they slumped to a third successive league defeat.

“We talked very early on about the fact that we would have to have a substantial run at some point,” Pearson said. “We are having a good run at the moment but I am not naive enough to think these things carry on indefinitely without working at it. We probably need to win another six games, maybe more – it depends how it pans out this year – but we have certainly put ourselves in a better position than we were a few weeks ago.”