The opening chance fell to Martin Odegaard - who was subbed off injured later in the first half - as the skipper struck just wide from the edge of the area.
Viktor Gyokeres was then given an opportunity to open his Arsenal account, but he dragged wide with more time in the box than he perhaps thought. Leeds caused a scare from a corner as Pascal Struijk’s header was pushed over well by David Raya.
However, the Gunners found the breakthrough with their own corner, as Declan Rice swung in for Jurrien Timber to brilliantly head into the far corner.
After also doing so against Manchester United last weekend, it is now the 32nd goal Arsenal have scored from a corner since 2023/24 - by far the most in the top flight.
Timber then turned provider to double the hosts’ lead just before half-time, as he fed Bukayo Saka and the winger struck superbly first-time into the net with his weaker right foot.
Arsenal found a third almost immediately in the second half as Riccardo Calafiori fed Gyokeres through the channel, and the Swede cut into the box before striking into the near post for his first Gunners goal.
However, that joy was short-lived as Saka went off injured moments later, but Arsenal got a fourth through yet another corner as Timber poked home again after a scramble in the box.
The hosts could then afford to give 15-year-old Max Dowman his league debut as he came on, and he looked lively as he won a penalty in stoppage time. Gyokeres stepped up and struck into the bottom corner for his brace.
Nonetheless, it was a comfortable victory as Arsenal shot up to the top of the table in its early stage, matching a Premier League record of 43 straight home games unbeaten against newly-promoted sides. Meanwhile, Leeds’ seven-match winning run comes to an end.
Flashscore Man of the Match: Jurrien Timber (Arsenal)
