Arsene Wenger says Arsenal keep making the same mistakes away from home, as proved in the loss to Newcastle.
Alexandre Lacazette's opener in the first half was a positive start for Arsenal and they had further chances to increase their lead at St James' Park but failed to take them.
Newcastle went on to win 2-1 thanks to goals from Ayoze Perez and Matt Ritchie, leaving the Arsenal manager confused by a fifth straight away defeat in the league.
"It is a little bit of the story of the season away from home: we went 1-0 up, we don't put the game to bed and we made mistakes defensively," Wenger said.
"But I felt overall today the fact we played on Thursday night [in the Europa League], in the second half we couldn't raise the tempo and keep it up in the first half.
"That is what happened many times this season, that's all we can say today. It's baffling how we lost this game today because from those chances we lose 2-1. On the other hand, the result is there."
Wenger was left disappointed that his team could not increase their lead rather than letting Newcastle into the game as chances were squandered before Perez's equaliser prior to the break, with Ritchie netting the winner in the 68th minute.
"We had lots of other opportunities in the first half and unfortunately there were promising things in our game many times but we live at the level where we need to be realistic and transform all the chances."
Arsenal are still in sixth, just two points above Burnley with Wenger now left to ponder how he can help improve his team's form away from the Emirates.
"How do we address it? By now making the same errors we have up to now, it's quite baffling because traditionally we have been very strong away from home. I believe as well that this week we had to give a lot on Thursday night and the players who played on Thursday night you could see the game was a bit in their legs."