Town maintained a 100 per cent home record against Scunthorpe thanks to sublime goals from Carlos Edwards and Jimmy Bullard.
Blues should have been ahead before Edwards struck midway through the first-half, keeping up his record of only scoring wonder goals for Town with a terrific strike from 30 yards to register his fourth goal of the season.
Bullard also took his tally to four since joining Blues from Hull on loan in January, curling a free-kick around the wall and into the net eight minutes into the second-half to set up a seventh successive win against Scunny at Portman Road.
Town made three changes to the side that went down at home to Watford in midweek, Arran Lee-Barrett coming in for his first game of the season, Josh Carson handed his first-team debut with David Norris returning from suspension.
Carson almost had a dream start to the game inside the first minute, Connor Wickham crossing from the left, Lee Martin nudging the ball past 'keeper Josh Lillis but the U18 skipper couldn't get on the loose ball before Michael Nelson hacked it clear.
Norris could have put Blues ahead two minutes later, bursting clear but he shot at Lillis from the edge of the box.
Bullard had another effort deflected as Town dominated the early exchanges before Grant Leadbitter was booked for a foul on Lee Miller.
Wickham headed wide from Bullard's cross, while at the other end Scunthorpe had their first sight of goal, Edwards coming to Blues' rescue as Miller looked to get in.
Lee-Barrett saved from Michael O'Connor's free-kick after a Bullard foul, Wickham then just failing to get on the end of Martin's cross.
The breakthrough came on 26 minutes, Edwards took possession, raced into the Scunthorpe half and then smashed in a superb strike from 30 yards.
Gareth McAuley couldn't keep his volley down from Bullard's corner, Carson went close with a header before the half came to an end with Martin dragging a shot wide after cutting inside the Scunthorpe defence.
Town had a penalty claim inside the first minute of the second-half, Martin going down in the box but referee David Webb showed the midfielder a yellow card rather than pointing to the spot, taking the former Manchester United player to the dreaded 10 yellow cards for the season and two match ban. O'Connor soon followed into referee Webb's notebook after catching Norris and Bullard made them pay with a top class free-kick, around the wall and into the bottom corner.
Scunthorpe made a first change on 56 minutes, Bobby Grant on for Ben Gordon.
Bullard fired wide from 25 yards, O'Connor then giving Lee-Barrett an anxious moment with a free-kick from 50 yards that landed on the roof of the net.
Norris sent a volley over before the visitors made a second change with Michael Collins on for Mark Duffy just past the hour. Carson's debut ended on 70 minutes with Andy Drury his replacement, McAuley then becoming the third Blue to be booked.
Chris Dagnall replaced Miller in Scunthorpe's final throw of the dice, Colin Healy also on for Leadbitter but Lee-Barrett was rarely troubled as Blues eased to a first home win in five games.
Town: Lee-Barrett, Edwards, McAuley, Delaney, Kennedy, Martin, Leadbitter (Healy 87), Norris, Bullard, Carson (Drury 70), Wickham. Subs not used: Fulop, Peters, Scotland, Priskin, O'Dea. Booked: Leadbitter, Martin, McAuley.
Scunthorpe: Lillis, Hughes, Nelson, Mirfin, Nolan, Duffy (Collins 62), O'Connor, Wright, Gordon (Grant 56), Garner, Miller (Dagnall 83). Subs not used: Slocombe, Togwell, Raynes, Reid. Booked: O'Connor.