With Manchester United, Manchester City and Arsenal all dropping points a day earlier, the Reds went in search of a potentially priceless victory to boost their Champions League aspirations at Vicarage Road.
And Can produced a moment of magic that will be repeated on highlight reels for years to come, his sublime bicycle kick enough to decide the match as Sebastian Prodl struck the bar for Watford late on.
Can's marvellous strike was a moment of relief for Liverpool, who were beaten 2-1 by Crystal Palace last time out, after the Reds lost star playmaker Philippe Coutinho to injury early in the game.
Ridiculous. pic.twitter.com/6BEepdd2sJ— Liverpool FC (@LFC) May 1, 2017
That prompted the return of Adam Lallana from the bench for his first Liverpool appearance since March due to a thigh problem and the England midfielder was unfortunate to see a wonderfully executed volley hit the crossbar with the match goalless.
Liverpool, who won the reverse meeting 6-1 in November, created the better chances after the break but one goal was enough for them to strengthen their hold on third and move four points clear of fifth-placed United, having played a game more while Watford stay 13th.
Coutinho was hurt in an innocuous-looking clash of legs with Adrian Mariappa and, shortly after, Miguel Britos hobbled off for Watford to be replaced by Christian Kabasele.
The injuries took the sting out of the opening exchanges, but Can almost brought some much-needed life to proceedings with a well-struck left-footed effort from 25 yards that Heurelho Gomes parried to safety on his 100th consecutive league appearance.
Both teams were struggling to stamp their authority on a turgid half until Lallana went desperately close to a goal-of-the-season contender with a magnificent dipping volley that crashed against the crossbar.
Lallana was outdone by Can's effort on the stroke of half-time, though. Lucas Leiva clipped a lofted pass into the area and the Germany international executed a spectacular bicycle kick that nestled in the top-left corner.
3 - Lucas Leiva has provided 3 assists in his last 5 Premier League games, as many as in his previous 163 top-flight apps. Renaissance. pic.twitter.com/Xq2BaaaS6C— OptaJoe (@OptaJoe) May 1, 2017
Watford beat Liverpool 3-0 in last season's corresponding fixture but offered little on this occasion, and Gomes had his palms stung by James Milner's 20-yard free-kick after the interval.
The goalkeeper was also equal to Divock Origi's bending effort from outside the box, while the striker was later wasteful when one-on-one with Gomes.
Simon Mignolet had largely been a bystander, but the Belgian made a fine fingertip stop to keep out a well-hit shot from Etienne Capoue, who was booked for remonstrating when referee Craig Pawson failed to spot the shot was saved.
A fully fit Lallana perhaps would have done better with a poor first touch when played in by Can, while substitute Daniel Sturridge was brilliantly foiled late on by Gomes.
Liverpool were almost caught cold in the last minute of injury time, but Prodl's fierce half-volley cannoned back off the crossbar, leaving the visitors breathing a late sigh of relief.
Key Opta stats:
- Liverpool have won three consecutive Premier League away games under Jurgen Klopp for only the second time (also in October 2016).
- Watford conceded for the first time in four Premier League home games, since losing 3-4 to Southampton at Vicarage Road on March 4th,
- James Milner made his 450th Premier League appearance in this game, the 22nd player to do so.
- Jurgen Klopp named the same Liverpool starting 11 for the third consecutive Premier League game, something he had only done once before, in December.
- Emre Can has netted five Premier League goals this season, more than twice as many as in his previous two combined (2).
- Lucas Leiva has registered three assists in his last five Premier League appearances, as many as in his previous 163 in the competition.