And no, it wasn’t because of the sweltering 37-degree heat, but instead the impressive performance of Arsenal’s Brazilian forwards.
For much of last season, Arsenal’s reliance in attack weighed on the shoulders of Bukayo Saka and, at times, Emile Smith Rowe too.
If the opening two games of this campaign are anything to go by, however, then that burden will be shared much more evenly.
Gabriel Jesus and Gabriel Martinelli were the stars here, with the latter scoring twice and claiming two assists as well to cap off a dream home debut.
Jesus was the undoubted star of the show and man of the match. His first goal was a thing of beauty, as he curled it into the top corner, while his second was a classic poacher’s effort of being in the right place at the right time as he headed home at the back post from a corner.
The striker’s first assist was a similar story as Leicester goalkeeper Danny Ward clumsily dropped a cross onto the Brazilian’s foot, allowing him to tee up Granit Xhaka for Arsenal’s third.
Arsenal look transformed with Jesus up front. He is bright and busy, both with and without the ball, and this attack should give plenty of teams problems this season.
A key part of it is the obvious chemistry between Jesus and Martinelli, which was on show against Leicester.
The pair just seem to know where the other will be and it was little surprise to see Martinelli involved in both of Jesus’ goals.
There is a huge buzz around Jesus after his £45million from Manchester City, but just as exciting is the new partnership he is forming with Martinelli.
The 21-year-old looks to have gone up a level from the player he was last season, particularly physically, and he is making his presence known.
Leicester defender Wesley Fofana will certainly be glad to see the back of him as he was given a torrid time by Martinelli, who pressed and harried him without the ball.
That is a major part of what Jesus and Martinelli offer and they have turned this Arsenal attack into a slick pressing unit.
No more was that clear then for Arsenal’s fourth goal, which settled what was otherwise going to be a nervy final 10 minutes after James Maddison had made it 3-2.
Martinelli pressed a sloppy Leicester pass, winning the ball back, and from there he took off.
The ball was fizzed to Martin Odegaard, to Jesus and then back to Martinelli, who found the bottom corner with his left foot from outside the box.
He turned away in delight, celebrating with Jesus as they rounded off what was the perfect afternoon for them and Arsenal.
The Gunners have now won both their opening games of the Premier League season and the mood compared to a year ago is completely different.
Back then, the club was in crisis as they lost three games on the spin.
This afternoon, it was like watching Brazil.