Morgan Rogers had an injury-time winner for Villa denied for a foul.
Watkins later said: "I think it was soft. Maybe in the Premier League, it's a goal. But in Europe, the goalkeepers are protected a lot. It's one of them.
"I thought we scored. But to be fair, this game had a 0-0 written all over it.
"Obviously, I have to be careful talking about the referee. But it's different in this competition. But we are used to it now. Sometimes it goes against you and sometimes it goes in your favour.
"It's a positive result. The fans want to see a lot of goal and we do ourselves. But the most important thing was we didn't lose tonight.
"Juventus are a massive team and they played well. But we kept them out and now we move onto the weekend."
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