David Luiz was keen to tell former manager Jose Mourinho that Arsenal's penalty was deservedly awarded.
The Gunners came from behind to win the north London derby at the Emirates.
Alexandre Lacazette's second-half penalty completed the turnaround after Erik Lamela's sublime effort had given the visitors the lead.
Martin Odegaard equalised just before half-time, but Michael Oliver's decision to point to the spot was the decisive moment.
Lacazette was through on goal and sliced his effort.
But Davinson Sanchez, in his attempts to block the shot, scythed down the Arsenal forward.
Oliver pointed to the spot, although VAR did its inevitable checks.
The Tottenham bench was less than impressed with the decision as Jose Mourinho led the protests.
But Luiz, who was in close proximity, simply said "it was a penalty" with a noticeable grin on his face.
Lacazette was able to send Hugo Lloris the wrong way to secure the three points for Arsenal.
Harry Kane, who endured a quiet afternoon in the capital, saw his late free-kick come off the post.
The win means the Gunners close to within four points of their rivals while Tottenham's top four chances were dealt a major blow.
Mourinho's side are six points off Chelsea but have a game in hand.
It is West Ham who have control of their own destiny however - enjoying a game in hand on Tottenham and two on the Blues.
