Brentford stunned Arsenal to win 2-0 on Friday night in the opening Premier League clash.
Brentford took to life in the big time with ease and fully deserved the lead given to them after 22 minutes when Sergi Canos drove low past keeper Bernd Leno at the near post, although Arsenal complained bitterly that the ball had gone out of play in the build-up.
Only Emile Smith Rowe truly rose above the mediocrity for Arsenal, forcing a save out of Brentford keeper David Raya - who also brilliantly denied Nicolas Pepe late on - before the home fans exploded in noise and elation when they scored a second with 17 minutes left.
Arsenal, without strike pair Alexandre Lacazette and Pierre-Emerick Aubameyang through illness, paid the price for a hopeless attempt to defend substitute Mads Bech Sorensen's routine long throw. New £50m defender Ben White was particularly culpable as Christian Norgaard arrived to head home.
Brentford boss Thomas Frank later said: "I think we top-performed but there must be a level above that. The fans were absolutely amazing. That was more than a 10/10 performance in terms of atmosphere. Constant singing. Amazing.
"I know after the play-off final there were a lot of proud people, a lot of tears. It's been a long journey.
"I thought we deserved the win. What I liked was how brave we were, pressing high and trying to play.
"If there was only one man of the match, it's the fans. I can't name one of the team, they were all top."
On Ivan Toney, he added: "Unbelievable presence, how he led the team. Constant battle with the centre-backs. He did many good things with link-up play and set-pieces in both boxes.
"We didn't have any Premier League experience - maybe 30 minutes. We believe if we have players with quality and the right character, then there's no problems.
"Of course this is one game. We have to prove it many more times. But this was a good start.
"Tonight I will enjoy it and get a glass of red."