Match ends, Arsenal 4, Leicester City 3.
Substitute Olivier Giroud headed in a dramatic late winner as Arsenal fought back to beat Leicester City in a thrilling start to the 2017-18 Premier League season.
The Gunners trailed 3-2 with seven minutes to go before Aaron Ramsey and Giroud swung the game back in the home side's favour at a euphoric Emirates Stadium.
Alexandre Lacazette headed the Gunners ahead 94 seconds into his top-flight debut, only for Shinji Okazaki to nod in an equaliser just two minutes later.
Vardy then slid the visitors ahead from Marc Albrighton's cross, before Danny Welbeck drew Arsenal level at the end of a pulsating opening half.
Leicester took the lead again when Vardy headed in Riyad Mahrez's corner before Arsene Wenger made an inspired double substitution which sparked Arsenal's comeback.
Substitute Ramsey smashed in an angled drive - from a corner which was won after Mesut Ozil handled in the build-up - before Giroud showed athleticism and strength to meet Granit Xhaka's corner.
Giroud proves his worth after deciding to stay
Giroud's days at Arsenal appeared to be numbered following the arrival of fellow France striker Lacazette from Lyon for a club-record £46.5m fee.
And Wenger revealed after Friday's win that Giroud, who has scored 97 goals in 231 appearances since joining from Montpellier in 2012, could have left the Gunners this summer.
"At one stage I opened the door for him as I knew I had many strikers, and in the end he decided to stay," said Wenger.
"He doesn't want to leave and I'm happy he wants to stay."
The 30-year-old wasted no time in proving his worth with another vital goal after coming on as a substitute.
Giroud offers a different, more physical option for Wenger, but is hoping for a more substantial role at the club.
Since the start of last season, he has scored seven Premier League goals when coming off the bench - three more than any other player in the same period.
"I prefer to be on the pitch as much as I can but I want to help the team reach the targets," he said.
Arsenal rally to avoid another opening defeat
Arsenal started the new Premier League season having won just one of their previous five opening matches - all of which were also home fixtures.
In the build-up to Friday's game Wenger repeatedly stressed the importance of beginning with a positive result against Leicester - and the Gunners appeared to have listened to their manager as they made the dream start.
Lacazette was perfectly placed to take advantage of Wes Morgan misjudging Mohamed Elneny's cross, flicking in a low header to become the fastest-scoring debutant in Premier League history.
The joy did not last long, however. Leicester exploited sloppiness by the Gunners to go ahead, leading to murmurings of discontent among the home crowd.
Arsenal's failure to finish in the top four of the Premier League for the first time in 20 years last season, not to mention the criticism Wenger has received from some sections of the Gunners support, meant the Frenchman could ill-afford to begin with a defeat.
And the mood ebbed and flowed inside the Emirates - with some of the familiar grumblings of discontent evident.
The atmosphere turned dark among the home fans after Vardy's first, the audible frustration subsiding when Welbeck calmly rolled in Saed Kolasinac's cut-back, only to return again when Vardy restored the Foxes lead.
Wenger looked on anxiously from the dugout, eventually appearing on the touchline when he introduced Ramsey and Giroud after 67 minutes.
Within 20 minutes both players had scored - and the mood completely changed - as Arsenal avoided losing their opening fixture for the fourth time in five years.
Leicester show glimpses of their title-winning form
Leicester manager Craig Shakespeare talked in his pre-match interview about the Foxes knowing their counter-attacking strengths and trying to use them to good effect against Arsenal's "fashionable" back three.
That is exactly what they did.
The visitors found joy down the flanks, exposing the Gunners' familiar defensive failings through Vardy's sharp movement and quick balls forward.
Their rapid breaks were reminiscent of their title-winning side of two seasons ago, as was their clinical finishing: the Foxes scored with each of their three efforts on target.
Unfortunately for the 2015-16 champions, it was their own lapses of concentration which could not keep Arsenal out at the other end.
Led by captain Wes Morgan and new signing Harry Maguire, Leicester remained resolute in the second half until the pressure from Arsenal - who had 27 attempts at goal - eventually told.
"Scoring three goals away from home is a positive and we'll get back on the training field to make sure we sort the problems out," said Vardy, who turned down a move to the Gunners last summer.
Man of the match - Jamie Vardy (Leicester)
Arsenal manager Arsene Wenger:
"We know defensively we can do better but overall we produced a top-quality game.
"When the substitutes came on they had enough quality to make the difference.
"I'm convinced that overall this kind of game can strengthen the belief. When you're in difficult situations you're reminded you've done it before so can do it again."
Leicester manager Craig Shakespeare:
"We spoke about being compact and being a threat with the pace of Vardy. We executed that well. We're disappointed to score three and come away with a defeat.
"When teams make substitutes just before corners it's confusing. I'm disappointed with the handball in the build up, but once the corner's given you have to defend it better. I don't know whether it was lack of concentration or game management.
Arsenal just love playing against Leicester...
- This was only the sixth time that an opening game in a Premier League season has seen seven goals scored - no game has seen more
- Arsenal are now unbeaten in 22 Premier League games against Leicester City - winning 15 and drawing seven - and they have won 11 successive Premier League home games against the Foxes
- Alexandre Lacazette scored with his first shot (and second touch) as a Premier League player
- The last player to score a goal faster on their Premier League debut was Thievy Bifouma, who came on for his Premier League debut for West Brom at half-time and scored after just 36 seconds in a 3-1 defeat at Crystal Palace in February 2014
- Lacazette is just the seventh player to score on his Premier League debut for Arsenal, after Kevin Campbell, Steve Bould, Fredrik Ljungberg, Emmanuel Adebayor, Samir Nasri and Thomas Vermaelen.
- Jamie Vardy has now scored five goals in his last five Premier League appearances against Arsenal
The rest of the opening Premier League weekend, of course...
After that, Arsenal go to Stoke City - a place where they have struggled in recent years, winning just one of their past seven trips - on Saturday, 19 August (17:30 BST).
Leicester return home as they welcome newly-promoted Brighton on the same day (15:00 BST).
- 16HoldingSubstituted forGiroudat 67'minutes
- 35ElnenySubstituted forRamseyat 67'minutes
- 23WelbeckSubstituted forWalcottat 75'minutes
- 5MorganBooked at 90mins
- 22JamesSubstituted forIheanachoat 82'minutes
- 11AlbrightonSubstituted forGrayat 88'minutes
- 20OkazakiSubstituted forAmarteyat 72'minutes
- Mike Dean
- Shots on Target
Second Half ends, Arsenal 4, Leicester City 3.
Attempt missed. Aaron Ramsey (Arsenal) right footed shot from outside the box is high and wide to the right. Assisted by Granit Xhaka with a headed pass.
Wes Morgan (Leicester City) is shown the yellow card for a bad foul.
Olivier Giroud (Arsenal) wins a free kick on the left wing.
Foul by Wes Morgan (Leicester City).
Offside, Arsenal. Sead Kolasinac tries a through ball, but Mesut Özil is caught offside.
Offside, Arsenal. Alexandre Lacazette tries a through ball, but Theo Walcott is caught offside.
Foul by Alexandre Lacazette (Arsenal).
Danny Simpson (Leicester City) wins a free kick in the defensive half.
Foul by Granit Xhaka (Arsenal).
Riyad Mahrez (Leicester City) wins a free kick on the right wing.
Substitution, Leicester City. Demarai Gray replaces Marc Albrighton.
Aaron Ramsey (Arsenal) wins a free kick in the attacking half.
Foul by Daniel Amartey (Leicester City).
Goal! Arsenal 4, Leicester City 3. Olivier Giroud (Arsenal) header from the centre of the box to the top left corner. Assisted by Granit Xhaka with a cross following a corner.
Corner, Arsenal. Conceded by Kasper Schmeichel.
Attempt saved. Alexandre Lacazette (Arsenal) left footed shot from the centre of the box is saved in the top centre of the goal. Assisted by Olivier Giroud.
Goal! Arsenal 3, Leicester City 3. Aaron Ramsey (Arsenal) right footed shot from the centre of the box to the bottom left corner. Assisted by Granit Xhaka following a corner.