Olivier Giroud has opened on how Arsenal dug deep to come from behind to beat Leicester City 4-3 in the 2017-18 Premier League opener at the Emirates Stadium Friday night.The French man understandably expressed his delight with Arsenal securing the comeback win and by extension avoiding an opening day defeat that has been the norm in the last two seasons.Arsenal 4-3 Leicester City: 5 things we learntThe Gunners trailed 3-2 heading into the final 10 minutes of the game, but Aaron Ramsey drew the hosts level before Giroud struck the winner with just five minutes left. Giroud insists that Arsenal's belief in their tactics and refusal to let their heads drop was crucial in turning the game around and claiming all three points.The France international told Sky Sports News after the game: "Obviously I knew that I was going to have a chance so we tried to push."We kept the faith and kept believing in our game to push hard. We've been courageous to the end and thank God we won the game."The winning goal scored Friday night by Giroud is his 50th at the Emirates in all competitions for the Gunners.