Arsenal staged their fightback after Okazaki came off in the 72nd minute.
Vardy bagged his brace when he capitalised on another piece of poor defending from the home side to fire Leicester into the lead in the 56th minute to make the scores 3-2.
The event which got people talking was undoubtably the goal scored by Gunners' new recruit Alexandre Lacazette who managed to find the net during his top flight debut in under two minutes, which installed great promise for the upcoming season.
"Once again, we had to come back and the team showed it was very well prepared because it could cope with the unpleasant situation", said Cech. "In the end he made a decision to stay and it was one of the great days of the recent weeks for me".
"I know that it's important for him to play".
Asked about Arsenal's title chances, Wenger said: "There are six or seven teams who can win the league".
Speaking to Sky Sports after the game, Wenger said of Giroud: "I love the man and the player". It was a relief for me he chose to stay.
Rumours persist that Sanchez will leave before the window closes, with Wenger suggesting he will also miss the trip to Stoke next weekend.
So have Arsenal finally grown a pair and instilled that elusive "winning mentality" into our side?
Typical Arsenal though, they conceded an equaliser just three minutes later when Harry Maguire headed back across goal excellently for Shinji Okazaki to nod home past a hapless Peter Cech.
Giroud then sent the previously despondent Arsenal fans wild when he headed the 85th minute victor from a corner, Leicester keeper Kasper Schmeichel only managing to turn the ball onto the underside of the bar before it bounced over the line.
"The first goal was from a short corner and we were not focused enough".
It's only the second time in eight seasons that Arsene Wenger's side have secured three points in their opening fixture. It's no doubt going to spoil all of us because the rest of the games are going to suck by comparison. What the game was, though, is a reminder that beyond the incessant transfer rumours and long, moody shots of Arsene Wenger staring into nothingness awaits the adrenaline rush that only a good game of football can give. You can not keep the strikers happy when they don't play.