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.
BBC