Teemu Pukki put Norwich in control. The Finland forward struck twice in the first half at Carrow Road to reach 20 goals this season.
Todd Cantwell scored a third for the Canaries as earned a seventh successive victory.
Daniel Farke's side is 10 points clear of Watford as it eyes an immediate return to the top-flight after last season's relegation.
The Hornets leap-frogged Brentford into second place after a 1-0 victory over Nottingham Forest at Vicarage Road.
With the Bees inactive after coronavirus cases at Rotherham United, Watford took full advantage courtesy of Adam Masina's 17th-minute goal.
Swansea City is one point behind Watford in third place after another dramatic late Andre Ayew penalty saw off play-off chasing Middlesbrough 2-1 at Liberty Stadium.
Ayew had the Swans ahead going into stoppage time, only for Sam Morsy's deflected effort to look like salvaging a point for Boro.
But, as against Stoke City in midweek, Ayew converted from the spot at the death to take his tally for the season to 13.
Reading maintained its position in the play-off places with a 3-0 victory over 10-man Sheffield Wednesday at Madejski Stadium.
Michael Olise converted from the penalty spot on the half-hour, after Julian Borner was sent off.
Lucas Joao struck his 21st goal of the season against his former side in the 65th minute before Andy Yiadom scored a late third.
A sixth consecutive defeat, the second in a row under new boss Darren Moore, left Wednesday still seven points from safety.
Daryl Dike's goal four minutes after half-time gave sixth placed Barnsley a 1-0 win against relegation-threatened Birmingham City at Oakwell.
Bournemouth slipped out of the top six after drawing 1-1 with Preston North End at Deepdale.
Blackburn Rovers claimed a first win in eight matches after goals from Bradley Dack and Sam Gallagher secured a 2-0 victory over Millwall at The Den.
Stoke City ended a three-match losing streak with a 2-0 success over bottom Wycombe Wanderers of the table.
Bristol City suffered a second consecutive defeat, losing 2-0 to Queens Park Rangers at Ashton Gates.
Maxime Biamou scored an early winner as Coventry City beat Derby County 1-0 at St Andrew's to move six points above the relegation zone.