Crystal Palace winger Wilfried Zaha was fuming after Brentford scored a late equaliser in a 1-1 draw at Selhurst Park.
The Eagles looked set for victory after Zaha's sensational second-half strike put them ahead.
But a lapse of concentration allowed Yoane Wissa to head home Vitaly Janelt's inswinging cross in the 88th minute.
Bees defender Ben Mee almost snatched victory for the visitors, but his header crashed off the crossbar.
Palace now have 5 points in their opening five games, while Brentford are in ninth place with six points.
"Just one lapse in concentration ruins all the hard work," the forward told BT Sport.
"We literally just had to keep it tight. As soon as we went into the lead, we just started to defend. I don't see why we do that.
"If we'd just continued to press on, I feel like we could have got a second and ended the game. We just killed ourselves in the end."