Television replays showed a banana skin present on the pitch as Arsenal celebrated their opening goal, scored by Gabon worldwide Pierre-Emerick Aubameyang from the penalty spot.
Sunday's win lifted Arsenal above their north London rivals and into fourth place in the table, leaving them eight points behind leaders Manchester City.
Dier headed home Christian Eriksen's free kick with half an hour on the clock before Heung-min Son won a penalty minutes later, which Kane converted to make it 2-1 to the Lilywhites in the 34th minute.
However, Xhaka picked up his fifth booking of the season with a foul shortly after half time and will now serve an immediate one-game suspension meaning the Swiss worldwide will now miss Wednesday night's trip to Old Trafford.
The Wales worldwide has spent over ten years at Arsenal, playing nearly 350 games for the club, and helping the Gunners win three FA Cup titles.
"Everybody has been asking 'when are we going to sign a defensive midfielder?' and now we have got that guy in Torreira. Disappointed with the result but looking forward to the next game".
Aubameyang (centre) opened the scoring with a 10th-minute penalty (Nick Potts/PA).
Pochettino said: "They made two changes and put another striker on in Lacazette and Ramsey".
"At the moment the most important thing is he's smiling, he has the commitment, the behaviour and the performances like yesterday - that's the best for him and for us". "I think it was a very good conversation", Emery said.