Arsenal came out on top in a fiery north London derby as Gabriel's second-half header gave them a crucial victory at Tottenham.
The Gunners were without captain Martin Odegaard and key midfielder Declan Rice through injury and suspension respectively and survived a stern examination from Ange Postecoglou's side to spark ecstatic scenes at the final whistle.
Arsenal keeper David Raya excelled in the early stages to keep Spurs at bay with fine saves from Dejan Kulusevski while Spurs opposite number Guglielmo Vicario had to be at his best to keep out Kai Havertz's header.
Tempers boiled over late in the first half as players from both sides clashed following Jurien Timber's challenge on Pedro Porro, setting the stage for a tense second period.
And it was Gabriel who made the vital contribution after 64 minutes, escaping the attentions of Cristian Romero to rise and power Bukako Saka's corner high past Vicario.
Arsenal always relish any derby victory at Spurs but this one will taste especially sweet as it was achieved without two such significant figures in Odegaard and Rice while providing the perfect platform for next weekend's visit to champions Manchester City.
The Gunners, in the modern football parlance, suffered at moments in an occasionally bad-tempered encounter but - as at Aston Villa earlier this season - they dug deep and showed real grit to stay in the game before Gabriel's thumping header settled the game.
Arsenal then defended with determination to close out the three points, match-winner Gabriel and goalkeeper Raya delivering towering performances as Spurs eventually ran out of ideas.
Such are the fine margins in the Premier League because of Manchester City's supremacy, any failure to win is seen as a slip and after drawing at home with Brighton, Arsenal's victory assumes greater importance because they go to the champions in their next league game.
Manager Mikel Arteta will take extra pleasure in the way Arsenal coped without the quality and calming influences of Odegaard and Rice in the engine room - a fact reflected by the joyous reaction of players, management and supporters at the final whistle.
They were reflected in the goal as Spurs once again failed to defend a set-piece, a constant Achilles heel in the Ange Postecoglou era.
Last season, excluding penalties, Spurs conceded 16 goals from set-pieces out of 54 conceded. Including penalties it was 23 from 61.
Postecoglou appeared unconcerned by this obvious weakness but another crucial goal leading to a defeat from a routine corner poorly defended should focus the manager's mind, with three of Arsenal's last four goals against Spurs coming from set plays.
In the wider context, there was plenty to admire in Spurs' early endeavour but the longer the game went on the more wayward they became, descending into a catalogue of poor decision-making and failures to deliver quality from good positions.
There was a growing sense that Arsenal would punish these flaws and so it proved, much to the frustration of Spurs fans, who created a thunderous atmosphere as Postecoglou's side opened with verve but without end product.
This will be a bitterly disappointing day for Postecoglou and his players as Arsenal's absentees presented them with a big opportunity to make a statement, instead they fell short once more and now have only one win from their first four league matches.