Having collected one point from a possible nine going into the clash at the Riverside, Gianfranco Zola's side looked on course for a much-needed victory having come from behind to lead 2-1 going into injury time.
But Daniel Ayala headed a last-gasp leveller for Boro to ensure the shares were spoiled, leaving Hornets wing-back Pudil a frustrated figure.
"Everyone is disappointed because we think we deserved to win the game," he told the club's official website.
"We played well but we gave it away again in the last second. I don't know what to say. It's twice, maybe three times we have conceded a goal like that.
"We're disappointed because we worked really well during the week, we spoke about the attitude and about concentration.
"We gave everything on the pitch but one ball, one mistake, cost us. We have to improve. Maybe when we were leading 2-1 we had to score another and kill the game early.
"We have to be sharper. At 2-1 they gave us two or three balls on the edge of the box and we could have scored a third or a fourth and we would be celebrating right now."
Pudil added: "To come away and play better is good for us. We did everything to win, we just didn't quite make it. Still we have one more point and there are a lot of games in the future."
- Sports & Recreation
- Gianfranco Zola
- Daniel Ayala