Arsenal’s season, which has begun amid so much optimism and verve, descended into tumult and acrimony at The Emirates after referee Chris Kavanagh’s hugely controversial decision to send off Declan Rice reduced the Gunners to 10 men four minutes into the second half of their clash with Brighton & Hove Albion.

Arsenal dropped their first two points of the season in front of an enraged sell-out crowd in north London after Kavanagh showed Rice a second yellow card for nudging the ball away from Joel Veltman as Brighton tried to take a quick free kick.

The home side, leading through a first half strike from Kai Havertz, conceded an equaliser to Joao Pedro eight minutes later and much of the rest of the game was played against a backdrop of angry chants of ‘you’re not fit to referee’.

Kavanagh’s decision to dismiss Rice, who had been rightly cautioned in the first half for a reckless challenge on Veltman, might have been technically correct but in the context of the moment, it also felt deeply flawed.

The ball was rolling as Veltman tried to take the free kick, for a start, so presumably Mr Kavanagh would have had to bring play back anyway if Veltman had been allowed to punt it upfield in the first place.

The draw pricked Arsenal’s bubble after their unbeaten start to the season and the Deadline Day loan signing of Raheem Sterling from Chelsea.

The lesson of the last two seasons, when Arsenal have finished runners-up to Manchester City in the Premier League, is that you cannot afford to slip up if you are to beat the blue machine from the north. This was a slip-up.

Not that Brighton will be a push-over for many teams this season. They, too, had won their first two matches, including a victory over Manchester United, they spent more than any other team in the summer transfer window and they were still very much in the game even before Mr Kavanagh’s contentious decision to dismiss Rice.

It had taken Arsenal seven minutes to make their first real chance of the game and they fashioned it beautifully. Saka, who had already caused the Brighton defence moments of anxiety, played a short ball to Martin Odegaard and then set off for the return.

Odegaard lifted the ball delicately over the Brighton defence into Saka’s path but the England winger sidefooted his volley tamely at Bart Verbruggen. It was an escape for Brighton but they could not shackle Saka.

Arsenal spurned another chance 10 minutes later when Ben White drilled a superb crossfield pass to Leandro Trossard and Trossard’s cross curled into the path of Odegaard. Odegaard met it on the volley eight yards out but hit it a tentative effort too close to Verbruggen.

Arsenal’s failure to convert their dominance into a lead began to prey on their play. Even though they lost their most experienced player, James Milner, to injury, Brighton crept back into the game. Arsenal got sloppy in possession. Kaoru Mitoma dragged a volley just wide.

When Arsenal’s opener came seven minutes from half time, it came not from a patient build-up but from a hoiked clearance out of defence by Jurrien Timber.

Lewis Dunk should have cleared the danger when he contested the ball with Saka as it fell from the sky but somehow he failed to win the header and Saka clipped the loose ball into the path of Havertz. Havertz ran on to it and lobbed it over Verbruggen into the empty net.

Fabian Hurzeler, who engaged in a series of enthusiastic, angry and passionate diatribes against the officials all afternoon, was eventually booked for an overwrought contribution to a Declan Rice foul on Joel Veltman that earned the England midfielder a yellow card. Hurzeler is not, it appears, from the stoic school of modern managers.

Four minutes after half time, the game took a bizarre twist. Rice and Veltman tangled again near the corner flag, the referee awarded a foul to Brighton and as Veltman tried to take a quick free kick, Rice nudged the ball away from him.

Veltman was committed to the clearance and kicked Rice on his follow-through, knocking him over. Arsenal’s players demanded retribution against Veltman but to their astonishment, referee Chris Kavanagh showed Rice a yellow card for delaying the free kick and sent him off. Rice was flabbergasted.

Rice was dismissed, essentially, for delaying the restart of play. By the letter of the law, it was the correct decision by the referee although Arteta would be entirely within his rights to point to a moment in the first half when Joao Pedro kicked the ball away in front of the dug-outs and no action was taken against him.

There was some irony, then, in the fact that it was Joao Pedro who should bring the scores level eight minutes after Rice’s dismissal, which had changed the mood of the game entirely.

Dunk redeemed his error for the Arsenal goal by playing Yankuba Minteh through the middle. Minteh evaded the challenge of Gabriel and tried to drill his shot past David Raya. Raya beat it out but it fell to Joao Pedro who tucked it under his body into the net.

The Emirates was in tumult now. The crowd roared its disdain for the referee at every opportunity and cursed his treatment of Rice and his every move thereafter. Brighton sensed their opportunity and threatened more and more.

But 15 minutes from the end, Arsenal should have taken the lead. Havertz was played through on goal but when he tried to slide the ball past Verbruggen, Verbruggen stretched out his left leg and blocked the shot. It fell to Saka but his attempt was blocked, too.

The chances came thick and fast now. Substitute Yasin Ayari saw his shot well saved by the legs of Raya as the Brighton midfielder tried to wrong-foot him and, at the other end, Saka raced on to a cross but could only direct his sliding shot straight at Verbruggen.

Brighton desperately tried to force a winner in the six minutes of added time but Arsenal’s ten men held on admirably. All that was left was for Mr Kavanagh to run the gauntlet of angry fans as he walked back to the tunnel.