Emery's side climbed two points above fourth-placed Tottenham and fifth-placed Manchester United to bolster its chances of qualifying for the Champions League via a top-four finish with seven games to go.
Even though the Welsh International and Frenchman scored the goal, midfielder Mesut Ozil made the headlines with a fantastic display to lift the Man of the match award.
Unai Emery's side are in fine form having won their last 10 home Premier League games. We are in a good moment, a good mentality with the players.
"You can have players who look brilliant and have great games but when you analyse their game afterwards you say 'what did you do, where is the product?' We are happy", Lacazette told Sky Sports.
Sarri set to give Hudson-Odoi first EPL start
It was Cardiff's 17th successive defeat against a side now in the top six and leaves them in real danger of relegation. Chelsea fans turned on Sarri during their 2-1 win at Cardiff . "Probably we started the season too well", Sarri said .
"We have been speaking all season about the final third, you have to spend £50 million, £75 million [to have players to make a difference]". The fans helped us to get third place.
"I think we are taking a good performance using a different system and different players", Emery said.
A run of three straight wins since that hiccup has restored some momentum ahead of the weekend's big match and the Dortmund captain has been doing his best to ease the pressure on his team-mates as they target their first Bundesliga title since 2011-12.
Emery insists it will still be tough to seal a return to Europe's elite club competition, but he is more concerned about establishing a positive rapport with the Emirates crowd than focusing on their league position. I think we are more confident and everybody knows what they need to do.
Arsenal's reported interest is perhaps, therefore, not hard to understand, but his signing could see an established first-teamer go back to square one.