It was Watts' clutch relieving mark drifting back into defence that eased the pressure after the Bulldogs had slashed a 44-point deficit to two points.
"We haven't been in that situation a lot where we're 40 points up," Watts told AFL.com.au after the match.
"Once the Doggies started getting that run, it was hard for us to pull them up. We just had to try and stay calm, and fortunately for us there was not another five minutes to go."
Interim Melbourne coach Neil Craig was full of praise for Watts, who has received his fair share of criticism since he was drafted at pick number one.
"The last little bit of the game, his positioning, his capacity to know where to go, to read the play, he's got a cool head on him," Craig said.
"He's had sort of an all-round game tonight. He's been like that now for two to three weeks. He's taking some steps forward, Jack. He should feel really good about himself, because he's had to put up with a lot in this competition.
"I'm really pleased that he's actually able to show some of his talent, and he's actually worked on that, and addressed it pretty strongly."
Watts booted four goals in the win – the Demons' second of the season and their first under Craig.
"For me, (my form) has stemmed from other things," Watts said.
"I've lifted that intensity at the ball and my defensive work rate and that kind of thing has been high the last couple of weeks. I'm getting myself into positions where I haven't normally gotten myself. I still probably left a couple out there. I had a couple of shockers."
Watts could be seen encouraging his teammates and congratulating them for their work from the beginning of the game, and said he's doing his best to play a leadership role out on the field.
"Definitely trying to, that's for sure," Watts said.
"I just want this club to succeed. How much fun is that when we win games and play the way that we did? It's a completely different feeling to earlier on in the year, and that's why we play footy.
"Imagine doing that every single week. That's what I want so badly."
Jacqui Reed is a reporter for AFL Media. Follow her on Twitter @JacquiReedAFL
