Mateta struck a wonder goal on 83 minuntes to earn the point for the Eagles.
The French striker later said: "When I started on the bench I could see he (Arsenal goalkeeper David Raya) was very high up the pitch.
"So I knew if I won the ball I could try, so I did and scored. It is one of the best goals of my career. I thought it hit the crossbar but thankfully it was in!
"We have struggled for the last three games but we just listened to the gaffer and today was a good game for us."
"I am very happy. Hopefully I will score more goals. 14 goals is good but I hope for much more."
On their FA Cup semifinal with Aston Villa on Saturday, he added: "We can go in with confidence and hopefully we will win the semi-final. It is a very big game for the fans, for everybody and I can’t wait to play on Saturday."