Johannes Thorup joined Norwich from Danish side Nordsjaelland in May
Norwich City impressively earned their first home league win under new boss Johannes Thorup as they thrashed Watford at Carrow Road.
The hosts made a flying start as Josh Sargent went close after 80 seconds before Callum Doyle's excellent long-range opener two minutes later.
But Watford levelled when Ryan Andrews' accurate low effort snuck in after Rocco Vata had struck the Norwich post.
However, Borja Sainz put Norwich back in front in first-half stoppage time before Marcelino Nunez's cool finish for the Canaries' third early in the second half killed the game off.
The rout was complete when substitute Ben Chrisene scored his first senior goal in the final minute.
Norwich's win - their second in the league this season - moves them into the top half of the Championship table, in 11th, while a third game without a victory meant Watford dropped to eighth.
Callum Doyle scored for the first time since joining Norwich City on loan from Manchester City
Sargent's early sliding effort from Sainz's teasing ball across the face of goal was denied by a good save from Daniel Bachmann, but Norwich's fast start was rewarded soon after.
Doyle picked up the ball in midfield, skipped past Giorgi Chakvetadze and blasted home from the edge of the box as Bachmann failed to keep out the effort despite getting two hands to it.
Watford's Tom Dele-Bashiru blazed over from 12 yards after a half-cleared corner just two minutes later before the Hornets were rocked by two injuries as defender Francisco Sierralta and Bachmann both had to come off inside the first 12 minutes.
Bachmann's replacement Jonathan Bond was almost beaten by a stooping Sargent header that went wide - and the ball was in the net when Sainz broke clear and scored, only for it to be ruled out for a tight offside decision midway through the first period.
Having weathered the early pressure, Watford levelled as Chakvetadze played in Vata who struck the upright, but the ball was gathered by Ken Sema who lofted a cross to the far post where Andrews coolly slotted between defender and goalkeeper.
Tom Cleverley's side could not believe they were not ahead after 32 minutes when Chakvetadze's corner was deflected onto the post by Doyle and Dan Jebbison managed to blaze the rebound wide from a yard out.
But just as both sides expected to go into the break level, Sainz showed a superb touch to latch on to Kenny McLean's long ball and calmly finished with his left foot in the third minute of stoppage time.
Norwich kept up the pressure after the break as Bond did well to save Ante Crnac's effort before Nunez caressed Doyle's cross from the left into the far corner after another good ball by McLean.
Impressive Watford substitute Kwadwo Baah came closest to pulling a goal back as Chakvetadze played him through, but the 21-year-old German could not beat Angus Gunn in the Norwich goal.
The Canaries added a fourth as two substitutes linked up when Jack Stacey bore down the right and cut the ball back to Chrisene, who tapped in unmarked from close range for his first goal since his summer move from Aston Villa.
Thorup hails Norwich performance - reaction
Norwich head coach Johannes Hoff Thorup:
"I think with the football we have played so far this season we should have a few more points and I certainly feel we are moving in the right direction.
"We are not where we want to be yet and we will keep working hard at it until we get there. But I think this was the best performance since I’ve been here.
"We knew how important it was to start well – it gives confidence in the side, brings the crowd into it, and I thought we played some really good football and scored some beautiful goals.
"I was so pleased for the players – it hasn't always been the case this season but today they were rewarded with three points for a really good performance."
Watford head coach Tom Cleverley:
"We conceded early again and they had a very good chance to score before that. In the second half we also nearly conceded early again.
"Obviously we will have to work on our game plan for the first 10 minutes and we will keep doing that until we get it right.
"I wanted to come here and be high energy, be on the front foot – it was also like that when I played – but sometimes you can be open as a result and be punished for that.
"I think we have shown enough this season to prove we can be a top team but it is a case of getting the balance right going that other way."
