It was West Ham United surprising Arsenal 2-0.
Arsenal manager Arsene Wenger says his side didn't have fundamentals.
"I felt we were a bit nervous, yes, and we rushed a bit our game and we didn't respect always the basics. We wanted to be too quick going forward in the first half maybe. I don't think we were too confident, I would rather say too nervous maybe."
In other EPL action, it was Liverpool over Stoke City 1-0.
Liverpool manager Brendan Rodgers says they're happy to walk away with an away victory.
"It's always difficult when you come to Stoke. It's never an easy game here. But to get a win and perform on the back of where we were eleven weeks ago, I thought it was an outstanding collective performance."
Liverpool was embarrassed by Stoke 6-1 at the end of last season.
In other action from Sunday,
Newcastle United and Southampton drew 2-2.
On Saturday, It was Man United opening its season with a victory, getting past Tottenham 1-0.
EPL newcomers Watford earned their first point, levelling with Everton 2-2.
It was Liester City over Sunderland 4-2.
Crystal Palace dumped Norwich 3-1.
And Aston Villa potted a 2nd-half marker late to get past newly-advanced Bournemouth 1-0.
