Arsenal let a two goal lead slip to draw 2-2 against Watford at Vicarage Road on Sunday.
Pierre-Emerick Aubameyang scored two goals in the first half but Watford produced a great comeback in the second half with goals from Tom Cleverley and Roberto Pereyra.
It was Watford's first match since rehiring Quique Sanchez Flores as head coach after sacking Javi Gracia during the international break and Arsenal boss Unai Emery admitted his countryman's side gave them fits with their physical play.
"They are more stronger than us so we want to break the lines from the goal kick and connect to Mesut Ozil, like we did with the first goal," he said.
"We have young players, we are working to improve and they will gain experience from matches like today. We can grow up and learn with these mistakes."
Arsenal playmaker Mezut Ozil made his first appearance of the season after missing the opening day due to a security incident.
Watford started the game brightly and Gerard Deulofeu and Cleverley forced early saves from Bernd Leno in the opening stages.
But it was the visitors who took the lead when Dani Ceballos won the ball on the halfway line and Sead Kolasinac raced into the box and set up Aubameyang for his first goal.
The Gabon international scored his second with a tap-in 10 minutes later after Ozil and Ainsley Maitland-Niles exchanged passes.
Watford got back into the game after the break through a Cleverley strike after a defensive mistake from Sokratis Papastathopoulos.
After dominating the second half, Watford levelled with less than 10 minutes remaining through a Roberto Pereyra after he was brought down by David Luiz.
Abdoulaye Doucoure had a wonderful chance to win the game in the stoppage time but his shot went straight to Leno.
"I was really happy with the performance of the players," Sanchez Flores said. "We have one point against a very tough team. It's good for our confidence. We are positive."
Victory would have put Arsenal into third place but they ended the day seventh in a cluster of clubs on eight points.