Arsene Wenger hit out at a "scandalous" penalty decision after Arsenal lost their way and slumped to a 2-1 defeat at Watford.
Arsenal were leading through Per Mertesacker's first-half goal and had chances to make the Premier League game safe.
However, the Hornets got back in it through Troy Deeney's spot-kick, which came after referee Neil Swarbrick adjudged Hector Bellerin to have fouled Richarlison.
Tom Cleverley capped the home side's impressive comeback with an injury-time winner, but manager Wenger was left disappointed about the penalty decision.
"I believe that we had many, many dangerous situations where we could have scored but didn't. We had opportunities to score the second goal," he said.
"The decision on the penalty is a bit ridiculous and then we panicked a bit for their second goal and in the end we stand with a defeat.
"It is a scandalous decision, but what can we do about it? Nothing. We can talk and talk and talk. At the end of the day they scored.
"We dropped our level in the second half, we played very well in the first half. Despite that, we had the chances to score two and three."