A lone Ismaïla Sarr goal gave Xisco Muñoz the perfect start as Hornets' Head Coach with victory over Championship leaders Norwich City.

The expectations of attacking football came with the Spaniard's appointment, but this performance spoke of just more than threat to the opponent. There was defensive co-ordination, sensible pressing and then that much-trailed attacking intent; aided no question by a 4-4-2 formation which deployed key forward-thinking protagonists in their favoured roles.

The newly-installed coach swiftly restored club captain Troy Deeney to the starting line-up, alongside Andre Gray, with Ken Sema and Sarr in the wide midfield positions.

Étienne Capoue and Tom Cleverley provided know-how in central areas while Kiko Femenía was by far the most experienced operator in an otherwise youthful back line.

Muñoz's intent to have his players turn the Canaries' defenders towards their own goal was obvious from the start; by the ninth minute, Gray had got in behind the opposition rear-guard for a third time. The last of those came the closest to creating a chance for the Hornets' skipper but Gray's cut-back ran behind his strike partner Deeney.

And there was no denying Watford enjoyed the best of the first-half chances, despite Daniel Farke's Norwich having the lion's share of possession.

Capoue's round-the-corner lofted pass down the right on 13 minutes let Sarr sprint free of his full-back. Defenders smothered a potential Sema chance first up but the ball looped up kindly to Gray who thrashed a volley into the side netting.

The French midfielder was more villain on 19 minutes, raking down the Achilles of Emi Buendia with seeming intent and escaping lightly with only a yellow card. Kieran Dowell's resultant free-kick scuttled low then skipped up off the turf to force an alert gather from Ben Foster.

The Hornets took the lead on 39 minutes and could have doubled it soon after. Sarr it was with his fourth of the season, touching home at the far post from Sema's low cross from the left after Capoue, Gray and Jeremy Ngakia had all combined to release the Swede into space.

Just over two minutes later, Deeney should have doubled Watford's money but he totally mis-hit his volley from an inviting Femenía centre. Once again, Gray was well-placed to profit from the loose change but scooped a harder chance than earlier over the target.

City started and ended the half on the front foot; Max Aarons' third-minute run and tame shot and a Dowell 20-yard blast well over just before the break brought an enthralling first 45 minutes to a close.

Watford squeezed forward with intent from the restart - and put the league leaders firmly on the back foot.

Cleverley saw a 53rd-minute shot blocked behind, Sarr couldn't quite find Gray after pouncing on a slack Oliver Skipp cross-field pass and City keeper Michael McGovern had to beat away a fizzing cross from the Senegalese winger - who was named Sky Sports' 'Man of the Match'.

A trio of great situations that confirmed the Hornets' ascendancy. Norwich's crisp passing took a turn for the weaker and Watford's players sniffed the chance to put the game away.

Sema rescued an over-hit cross on the left and found Sarr with a 64th-minute cut-back. The winger's left foot shot was deflected wide to force a series of no less than six consecutive corners to confirm the host's dominant air.

But no question a sharp momentum shift was forced by wily Canaries' boss Farke, whose triple substitution with just over 20 minutes remaining saw a three-at-the-back approach yield his side far more possession.

One of the subs, Jordan Hugill, was presented with a choice to make six yards from goal but out wide. He chose the wrong option by shooting rather than passing, and, truth be told, the Hornets' defensive shape and willingness to block shots and cut off City's preferred passing lines paid full dividends.

A key moment apiece in the final 10 minutes of the match could have altered the scoreline - but neither did.

First, Hornets' sub Adam Masina was toe-perfect in touching the ball away from Norwich hotshot Teemu Pukki when poised to unleash a shot. Then fellow replacement Stipe Perica was presented with a golden chance thanks to Christoph Zimmermann's underhit back-pass but couldn't sort his feet out to put the game to bed.

Thus a nervy ending ensued for those in yellow, with Norwich trying to find that killer moment.

City pressed but never had that golden chance and Foster wasn't overly-extended in the Watford goal.

Star turn Buendia shanked wide at end of injury-time, summing up the visitor's performance on a night when the Hornets provided the Christmas cheer by cutting the deficit to the Sky Bet Championship summit to six points.