The Germany midfielder ran onto a lofted pass from Lucas and, with his back to goal, hooked a volley into the top corner.
With Jurgen Klopp's side sitting in third, it could prove to be a valuable goal as they push for Champions League football - but was it the goal of the season?
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"We scored a fantastic goal," Klopp said.
"Actually, I would love to see it again - everybody is speaking about it.
"I only saw it once but it looked already pretty nice. I turned a little early and didn't see it hit the back of the net.
"He is a good boy, a good player and he deserves it," added the German manager.
Liverpool have not been strangers to special goals this season - with midfielders Jordan Henderson, Sadio Mane and Georginio Wijnaldum all winning Match of the Day's Goal of the Month competition.
With 11 goals in 100 career league starts, Can is not the most frequent goalscorer, and the player admitted himself that his strike at Vicarage Road was his best to date.
"I have never scored a goal like that - maybe when I was younger. That is the best goal I've ever scored," Can said.
"I saw the space and I ran behind and my first thought was that I wanted to head it, then I didn't think too much."
Team-mate Adam Lallana, who made his return from injury as an early substitute, said that Liverpool players will be allowing Can to try more acrobatic efforts in training.
"He does like to try speculative efforts, and we will not have a pop now after he produced that," said the England midfielder.
"It was a 'worldy' goal, worthy of winning any game.
"Credit to him, he was brave enough to try it and it flew into the top corner."
The goal of the season will be chosen at the end of the campaign.
Tottenham's Dele Alli won the award last season for his strike at Crystal Palace, and the last Liverpool man to win the honour was none other than Steven Gerrard for his brilliant winner in the 2006 FA Cup final.
It was only his seventh Premier League goal since arriving from Germany three years ago, but Emre Can's sensational overhead kick was enough for Liverpool to beat Watford on Monday night.