His work at the breakdown was also key in the dying moments as some excellent defensive resolve helped repel Ulster, while No.8 Nasi Manu also played a starring role at BT Murrayfield.
A fourth straight win for Alan Solomons' side marks a fantastic return at the start of the new season and Watson believes there is no reason why that run can't continue.
"It was amazing. It was great to get the win against a good Ulster team, they are a very physical team and I think we fronted up to that," said Watson.
"Now we are four from four and we will be looking to just build on this. We've got Zebre next and we now need to concentrate on that.
"You could tell there was a great deal of support and you could really here the fans, thanks to them for coming along and hopefully we can keep the run going in the next game.
"It's great to have Nasi in the squad, he's a great player - we saw that in Treviso - and I think he's going to be really good at setting boys up for tries, Will Helu too.
"After this we now have another fifteen games on the bounce. We'll have to take one game at a time and try to keep this run going, see what happens."
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