Chelsea manager Frank Lampard let rip at his players following their 3-1 defeat at struggling London rivals Arsenal on Saturday, saying their "lazy" performance had cost them the chance of going second in the Premier League.
"It was an opportunity to go second against a team that are having a tough time," Lampard, whose side dropped to seventh, told Sky Sports.
"You either make it difficult for them or you give them a little opening and we did that from minute one and continued for 45 minutes. It was lazy to give away a penalty and lazy to give away a free kick that he [Xhaka] puts in the top corner."
"We fought ... but in the first half we gave ourselves too much to do... I'll take responsibility on the outside but the players also have to take responsibility," Lampard added.
"The message was clear, Arsenal are a dangerous team. When you go out and play 60% or 70% then you're not going to win any Premier League games."
Arsenal manager Mikel Arteta said he was delighted with the win that lifted his team to 14th.
"It doesn't get any better than winning a London derby against Chelsea on Boxing Day," he said. "Hopefully this is a turning point. I know they can play at this level.
"Let's carry on. We still have big things to improve on."