Arsenal midfielder Mikel Arteta has stressed the importance of scoring first following his team's 1-0 defeat at Norwich.
The Gunners fell behind to Grant Holt's 19th-minute opener and failed to overturn the deficit as Norwich clinched their first win of the Premier League season.
It was the fourth time in eight league games that Arsenal have allowed their opponents to net the opening goal.
And the Spanish midfielder, 30, has warned Arsenal must make their superiority in matches count if they want to challenge for top honours.
"It's not the first time we have conceded the first goal," said Arteta. "It's very difficult.
"If you go ahead it gives you a lift, the other team has to take risks and you can cause mistakes.
"You can't get back into the game every time you fall behind.
"It's a tough ask and we haven't done it."
He added: "For the amount of ball we had in the game, we should have done more and created more scoring situations.
"We are down because we know how good we are and good we can be."