The victory was preceded by the unveiling of new signing Eberechi Eze , whose move from Crystal Palace was confirmed as Gunners fans were taking their seats at the Emirates Stadium.
The England international got a great reception when he was presented to the crowd in the moments before kickoff.
Jurrien Timber opened the scoring after 34 minutes from a corner for set-piece specialist Arsenal before Bukayo Saka doubled the home side’s advantage on the stroke of halftime.
Gyokeres bounced back from missing an easy chance in the opening period to score on his home debut three minutes into the second half, powering into the Leeds penalty area before sending a low right-footed shot past Lucas Perri.
Saka and Martin Odegaard were both forced off with injuries but spirits were raised again when Timber landed his brace shortly before the hour mark.
Max Dowman, aged 15 years and 235 days, delivered an impressive second-half cameo from the bench when he became the second youngest player — after Ethan Nwaneri — to represent Arsenal.
And the teenager capped an eye-catching display by winning a penalty for his side in stoppage time which Gyokeres duly converted.
Meanwhile, Arsenal’s North London rivlas Tottenham continued their flying start to the Premier League season under new coach Thomas Frank as Brennan Johnson and Joao Palhinha secured an impressive 2-0 victory at Manchester City. (AP)