Arsenal boss Arsene Wenger was left to rue some missed chances and 'strange' refereeing decisions in a shock 3-2 defeat at Swansea.
The Gunners took an early lead through Robin Van Persie before Scott Sinclair's controversial penalty leveled the scores. Nathan Dyer put the hosts in-front before Theo Walcott's equaliser, but Danny Graham hit straight back at the Liberty Stadium to provide Brendan Rodgers' side with a notable scalp.
And, whilst the game was a thriller for the neutrals, it was a display in which Wenger was disappointed to see his defence come unstuck against the pace and passing style of their Welsh opponents.
"The game was difficult because Swansea played well. It was also decided by some strange decisions from the referee, who gave a penalty that was complete imagination," Wenger told the official Arsenal website post-match.
"From then on I thought there were some odd turning points, like when we came back to 2-2 and made a defensive mistake straight away. Our defensive performance was not good enough and that's why we lost the game. When we got back to 2-2 I thought we could win the game because I thought we could be dangerous.
"I think we also missed some unbelievable chances that are very difficult to understand and explain. But apart from that, well done to Swansea, they played well and deserved the win."
Defeat continues the Gunners' poor run of form in the Barclays Premier League, with just one win in the last four matches - against QPR.
And, with a draw against Wolves and back-to-back defeats against Fulham and now the Swans in that run, Wenger knows defensive frailties are emerging as a problem at the Emirates Stadium.
"Coincidences are always against us and it is difficult to understand what is going on. I don't know, I feel we are a bit too nervous. We cannot panic every time they have the ball in the final third of the pitch. We have to show more composure and ambition," added Wenger.
"It is always a concern but on the other hand there is a good spirit in the side and a desire to do well. But we have dropped six points in a row now that we should not have."
Arsenal remain fifth in the table, but now sit four points behind Chelsea in the final Champions League qualifying position.