Arsene Wenger admitted Middlesbrough deserved to end Arsenal's unbeaten start to the Premier League season but afterwards claimed he was happy with their form in the campaign so far.
The Gunners lost 2-1 at the Riverside Stadium on Sunday and remained just one point ahead of second-placed Manchester United in the table.
However, Wenger believes his youthful side will return stronger from their first league defeat of an impressive campaign.
"We lost the game because we deserved to lose it," said the Frenchman.
"It's that simple. Middlesbrough were sharper in the fight.
"We missed the start of the game by giving them too much room and it cost a penalty.
"From then on, it was down to us being a little bit jaded physically - it was our fourth away trip on the trot.
"We gave absolutely everything to come back. We lacked creativity, sharpness in our passing so therefore we were not dangerous enough to come back into the game.
"We have a few injuries at the moment, but it is easy to blame the players who are not here and I believe in the players who played today.
"This season will be a big, big fight for the title. United have had nine home games and seven away, while we've played eight each so I'm happy we're top of the league."