With the north London derby always featuring heightened intensity, passion, and pace of play, it appears Mauricio Pochettino was naive in suggesting that Chelsea had become Spurs' biggest rivals - especially after Tottenham's defeat against the Gunners. "In a hard moment in the first half, we kept calm".
Dier's equaliser came after Pierre-Emerick Aubameyang had put the Gunners ahead from the penalty spot.
Foyth largely acquitted himself well considering the occasion but he was at fault for Arsenal's third goal when his attempted pass was intercepted by Aaron Ramsey in the build-up to Alexandre Lacazette's strike.
The incident occurred after Aubameyang scored his first goal in Arsenal's 4-2 win at Emirates Stadium and celebrated near the travelling supporters at the Emirates Stadium.
Arsenal travel to Old Trafford on Wednesday evening as they bid to extend their unbeaten run to 20 games in all competitions.
That Arsenal finish strongly, overwhelming often exhausted opponents, is undeniable.
Ralph Hasenhuttl watching his new club struggle
For Tottenham, this was a third big game in nine days - following last weekend's victory over Chelsea and the midweek defeat of Inter Milan - and it felt like a bridge too far for exhausted players.
"Why? Because Lacazette has very big experience scoring against every opposition team".
"This conversation is not for today, for us or for me", he added.
The England worldwide was booked after celebrating Spurs players clashed with the home side's substitutes.
Injuries to Davinson Sanchez and Jan Vertonghen created an opening in the Spurs defence this season, with Foyth playing four times in the league. They have "won" 11 of those second halves.
That explains why Alderweireld - who played against Inter Milan in midweek and Chelsea last weekend - was benched for Spurs' match against Arsenal. Back spasms were also given as the reason when he missed October's win at Fulham.