Mikel Arteta's side saw its winning start ended by defeat at Manchester United in its previous league match, but the Gunners responded in emphatic fashion to move a point clear of Manchester City and Tottenham.

First-half goals from William Saliba and Gabriel Jesus put Arsenal in control, before Vieira – in for the injured Martin Odegaard – added a brilliant third after the interval.

With the points safe, Ethan Nwaneri, aged just 15 years and 181 days, became the youngest player in Premier League history as he appeared from the Arsenal bench for the closing stages.

Gabriel Martinelli slipped to spurn a glorious chance inside two minutes, but Arsenal soon punished Brentford for a timid start with two goals in quick succession.

Saliba met Bukayo Saka's corner with a near-post glance, which bounced off David Raya's right post and over the line before the goalkeeper could react, and then Jesus nodded in from Granit Xhaka's left-wing cross.

Saka and Kieran Tierney both fired off target from presentable opportunities, while Bryan Mbuemo flicked wide at the other end as Arsenal dominated the first half.

Vieira marked his full debut by whipping past Raya and in off the post from outside the area four minutes after the break.

Ivan Toney volleyed just over from an inventive free-kick routine, before Raya expertly denied a fizzing Jesus drive and a curling Saka effort as Brentford rarely threatened an unlikely comeback.