For Arsenal’s longsuffering supporters, the emotional strain is reaching unbearable levels. They could only watch in stunned disbelief as Alex Scott’s goal 16 minutes from time condemned the Premier League leaders to a defeat they must fear will prove to be extremely significant.

While Arsenal still lead Manchester City by nine points, a defeat at the Etihad next Sunday could give City an opportunity to draw level on points if they beat Chelsea tomorrow and then win their game in hand against Crystal Palace. Having set the pace since the start of October, that is the nightmare scenario Mikel Arteta and his team must now come to terms with.

Bournemouth, who have now gone 12 matches unbeaten, were excellent value for their second victory in succession here after Eli Kroupi Junior gave them an early lead. Viktor Gyökeres equalised from the spot, but there was a worrying lack of intensity from Arsenal throughout as the visitors made them pay dearly.

Bournemouth arrived determined to play the role of party poopers as Kroupi was deployed up front alongside Evanilson in a bold move from Andoni Iraola. The demands of a relentless schedule have tested Arsenal’s deep squad and the absence of Bukayo Saka for a fourth match in succession will be a major concern considering his importance to this team. Martin Ødegaard, the captain, was also missing with a knee problem so Kai Havertz stepped into the creative breach, while Myles Lewis-Skelly was handed his second Premier League start of the season at left-back in place of Riccardo Calafiori.

Arteta had definitely heeded his own pre-match message for supporters to get themselves up for the early kick-off and was a bundle of nervous energy on the touchline. Yet it did not take long for his anxiety to spread as Arsenal made a slow start and Bournemouth looked increasingly threatening on the break.

So it proved when Noni Madueke failed to track Adrien Truffert’s run in the 17th minute and Ben White was far too slow to react to the danger. Truffert’s cross looped off William Saliba to the back post, where Kroupi was waiting to tap in. The 19-year-old, who joined from Lorient last summer, is the first teenager since Robbie Keane to score reach double figures in his debut Premier League campaign and looks some prospect.

Havertz almost hit back immediately from a corner, but headed just over and the tension rose among the home supporters. A surge of relief spread around the ground when Michael Oliver pointed to the spot after Bournemouth failed to clear a Madueke corner and Ryan Christie handled in the ensuing melee, even if the Scotland midfielder clearly felt hard done by.

Havertz wanted to take the penalty at first, but Gyökeres insisted and Arsenal’s top scorer made no mistake from the spot to a huge roar of encouragement when the ball hit the back of the net.

Bournemouth continued to look dangerous and Evanilson tested David Raya from the edge of the area after White was again caught out of position.

It took only eight minutes of the second half for Arteta to act. Eberechi Eze, Max Dowman and Leandro Trossard were summoned from the bench in an attempt to inject some urgency. But a misplaced pass from Raya that almost donated an open goal to Evanilson showed that nerves were still affecting Arsenal’s players. They could not escape Bournemouth’s disciplined high press and Gyökeres had a goal disallowed for being well offside after he raced through to White’s long pass.

Declan Rice’s surging run ended with the England midfielder forcing Djordje Petrovic into a fingertip save as Arsenal tried to pile on the pressure. But there was always the nagging feeling Bournemouth could score again and those worst fears came true. Scott caught Martín Zubimendi napping and was able to latch on to Christie’s pass inside the area before beating Raya with a cool finish.

Gyökeres missed a golden opportunity to earn a precious point as desperation grew and it was Bournemouth’s supporters celebrating at the final whistle as Arsenal’s contemplated the unthinkable.