Arsenal's new signing Alexandre Lacazette scored in just 94 seconds to give Arsenal an early lead but Leicester responded in best way as Shinji Okazaki scored the equalising goal couple of minutes later and soon Jamie Vardy gave Leicester the lead.
He responded promisingly to Leicester's first equaliser by just missing the net, which happened a few times within the match and led to the England global becoming more visibly frustrated on the pitch.
Substitute Aaron Ramsey rifled home to level before Giroud - introduced alongside the Wales worldwide - headed in an 85th-minute victor to settle a breathless encounter in Arsenal's favour.
The fans will hope that the striking symbolism - Lacazette scoring Arsenal's and the EPL's first goal of the season on his debut - is an omen for good things to come this season.
"Obviously for the neutral it would've been a great start, just watching it from the outside", the former Manchester United striker said. "In the end he chose to stay and it was one of the great days of the recent weeks for me".
Arsenal is not just pursuing a first league title since 2004 but also a return to the top four " and Champions League qualification " after finishing fifth in May.
Marc Albrighton served in a ideal ball from the left, curling a cross for Vardy, who capped the sequence against the run of play with his first goal of the season.
Once they are back and available, Welbeck is hopeful that future results can be earned in less trying circumstances.
In general, Arsenal will have the upper hand because they play at home.
"We went for a win and we deservedly earned it".
Wenger, facing enormous pressure for going over a dozen years without winning the league, used some ballsy tactics, starting one center back (Rob Holding) in a 3-4-3 formation. "First game of the season we played a classic, so for everybody at home it will have been awesome to watch".
"It's a long time since we so much quality", Wenger said. He'll play 30 games, he'll give you 15 goals.