The Canaries made it nine straight victories at Carrow Road - just one short of the all-time record - as they saw off the plucky challenge of the relegation battlers.
Holt led the way with two goals to take his tally for the season up to an impressive 22 while strike partner Chris Martin also got in on the act, with veteran Exeter striker Marcus Stewart scoring what proved to be a consolation for the visitors.
Holt set the ball rolling after just eight minutes when he out-jumped Richard Duffy at the back post to head home Wes Hoolahan's looping cross.
Norwich finally got the all important second goal on 77 minutes when Martin stabbed home his 14th goal of the season from close range after Holt had speared a Simon Lappin cross into his path.
Exeter briefly threatened a comeback when Stewart coolly converted after Fraser Forster had failed to hold a shot from fellow substitute Liam Sercombe. But Norwich swiftly re-established their two goal advantage as Holt sprang the offside trap before coolly beating keeper Paul Jones to take the Canaries to within six points of leaders Leeds.