Arsenal's performance was desperately average throughout, hanging on in a scrap and barely creating a chance - and yet the result was greeted like a title win itself.
Saka's fortunate early strike, aided and abetted by the hapless Bart Verbruggen, was a rare moment of danger for Brighton, who set the tempo throughout.
And yet, as Brighton's efforts became more laboured, Arsenal survived the storm to celebrate at the final whistle, the noise from the travelling supporters coming to a crescendo when news of Forest getting a draw at Etihad Stadium filtered through.
Arsenal were in retreat for most of the game, their cause not helped by a lack of creation and ability to maintain possession or hold the ball up front, with Viktor Gyokeres anonymous before being substituted.
At the heart of it all was defender Gabriel, magnificent with his usual partner William Saliba out injured, almost mounting a one-man barrier of defiance as Brighton pushed.
The celebrations at the final whistle on and off the pitch reflected the importance of the win as Arsenal fans chanted "We're going to win the league".
And it is results like this, on nights like this, when titles are sometimes won.