Welbeck scored his first for the club since joining them in July as they beat bottom side Norwich City 2-1 on Tuesday.
Having struggled with injury during his five-year spell at former side Arsenal, Welbeck's problems appeared to continue at Watford after he injured his hamstring in October.
Pearson hailed the striker's hard work and commitment and that his dedication to getting fit has finally paid off.
"He's a player with a lot of ability and he's had a really good career. To have a winner of such quality is great for us because it was a difficult game," Pearson told reporters.
"I'm pleased for Danny, but I know him, he'll see this as a step in the right direction for himself having had a frustrating time with injury.
"So for him I know he will feel that all the hard work that he's put in to get himself back to match fitness has paid off. The goal was an added bonus, but I thought he played and worked exceptionally hard for his team."
The victory left 17th-placed Watford with 31 points from 34 matches, four points above the relegation zone.