Arsene Wenger was left frustrated after Arsenal conceded a controversial late penalty against West Brom, saying it was "difficult to accept".
The Gunners looked to be heading for victory at The Hawthorns after Alexis Sanchez's 83rd-minute free-kick deflected in off James McClean.
However, West Brom levelled in the final minute from the penalty spot after Calum Chambers was penalised for handball in the box.
Wenger, who was clearly annoyed by the decision and waited to speak to referee Mike Dean in the tunnel afterwards, said: "It's disappointing to see that but what can you do? You can talk and talk and talk but it doesn't change anything.
"I would like to remind that I did fight very hard with David Dein [former FA vice-chairman] many years ago that the referees become professional but their level, unfortunately, doesn't go up."
Asked whether the decision was 100 per cent wrong, Wenger replied: "Yes in my opinion. It's difficult to accept. It's more than the decision that is involved in that and it is not the first time it has happened. But it's best we don't talk about. We know deeply what it is going on and we just have to deal with it."
Wenger also said he welcomes the introduction of Video Assistant Referee technology, which is set to be used in the FA Cup next weekend.
"It's time," he said. "I don't know why we want to be the best league in the world and wait for such a long time when other leagues use it already."