Tottenham Hotspur lost their fourth Premier League match of the last five on Wednesday, falling 2-1 to Arsenal in the North London derby at the Emirates Stadium.
Spurs were outplayed from the opening whistle as the home side looked to assert their dominance early, but Tottenham actually managed to score first as talisman Son Heung-min's speculative shot from distance in the 25th minute struck an Arsenal defender and beat goalkeeper David Raya to give the visitors the lead against the run of play.
However, Arsenal continued the pressure and scored an equaliser in the 40th minute before notching the match-winner four minutes later.
And while Spurs were better in the second half, it wasn't enough to deny the hosts a crucial victory as Arsenal continue their pursuit of league-leading Liverpool.
For Tottenham manager Ange Postecoglou, Wednesday's result came off the back of a poor performance by his side, which continued a troubling trend as the team remained in 13th place and winless in five league matches.
"Nowhere near good enough, especially in the first half," Postecoglou told TNT Sports. "We were too passive. We let Arsenal dictate the game.
"Second half was a little better not nowhere near good enough. Not acceptable.
"Ultimately the responsibilty lies with me and how I prepare the players.
"I'm more interested in how we play and we were not anywhere near the levels today."