Goals from Kayden Jackson, James Norwood and Alan Judge have given Town a 3-0 half-time lead over Accrington Stanley at Portman Road.
Boss Paul Lambert named the same team which drew 1-1 at leaders Wycombe on New Year's Day with Will Norris in goal, skipper Luke Chambers, James Wilson and Luke Woolfenden the back three and Gwion Edwards and Luke Garbutt the wing-backs.
In central midfield, Flynn Downes was joined by Emyr Huws with Alan Judge ahead of them behind strike pair Kayden Jackson and James Norwood.
Accrington, who beat Town 2-0 at the Wham Stadium in October, made three changes from the team which beat Fleetwood on penalties in the Leasing.com Trophy on Tuesday with Mark Hughes, Colby Bishop and Wilson Carvalho starting, while Aji Alese, Ben Barclay and Offrande Zanzala dropped to the bench.
Town, looking to end their 12-game all-competitions winless run, started brightly with Jackson making a promising third minute run into the box. However, the former Accrington striker was forced wide and his cross was diverted behind. The resultant corner fell loose in the area but was cleared.
On nine Edwards whipped over a cross from the right which Callum Johnson nodded away ahead of Norwood at the far post.
A minute later Stanley, who have become something of a bogey side for the Blues over the last couple of seasons, made their first foray into the Town box but Joe Pritchard went to ground very easily in the box.
But it had mainly been the Blues and in the 12th minute they went in front. Garbutt played a clever pass in behind the Accrington left-back and overlapping centre-half Woolfenden cut across to Jackson, who stabbed home from a few feet out against his old club.
The striker was delighted to net his eighth of the season and end a 12-game goal drought, his last having come at Southend in October.
Two minutes later, it might have been 2-0, Norwood failing to make a connection when well placed after Edwards had knocked down a deep cross from Woolfenden.
Town continued to dominate with both outside centre-halves, Woolfenden and skipper Chambers, pushing forwards.
On 23 Accrington keeper Josef Bursik failed to hold a Jackson cross from the right after a neat interchange on the right but Garbutt could only loop the loose ball behind from a tight angle on the left.
Six minutes later it was 2-0. Huws played a long ball over the top from inside the Town half sending Norwood away behind the Accrington defence. Keeper Bursik made an uncertain half-advance to the edge of his area and into no-man’s land, and the Blues’ striker delicately chipped over him and into the net for his 10th of the season.
The visitors managed their first shot at goal on 33 but Sam Finley’s effort was allowed to roll past his left post by Norris.
Town should have made it 3-0 in the 36th minute when Jackson used his pace to break away on the right before cutting back to Norwood from the byline. However, the former Tranmere man scuffed his first-time shot well wide.
The Blues had another chance to extend their lead in the 42nd minute when Judge sent Jackson away in on goal but Bursik came off his line to block.
But two minutes later it was 3-0. Chambers picked up the ball deep and brought it forward before feeding Norwood, who returned the ball to his captain by now on the edge of the box. Chambers turned it on to Judge to his left and the Irishman beat Bursik to claim his first league goal for the Blues in his 39th league appearance for the club.
Not long after the whistle ended as good a first half as the Blues have enjoyed this season. Virtually from the off Town were on top, with the centre-halves notably breaking forward Sheffield United-style.
Jackson’s well-worked early goal settled any nerves there might have been following the Blues’ winless run and the scoreline could easily have been 5-0 at the break had Norwood and Jackson taken their later opportunities.
Town: Norris, Woolfenden, Chambers (c), Wilson, Edwards, Downes, Huws, Judge, Garbutt, Jackson, Norwood. Subs: Holy, Donacien, Skuse, Bishop, Dozzell, Kenlock, Keane.
Accrington: Bursik, Johnson, Hughes, Sykes, Finley, Pritchard, Bishop, Carvahlo, Conneely (c), Charles, Opoku. Subs: Savin, Zanzala, Barclay, Rodgers, Alese, Diallo. Referee: Charles Breakspear (Surrey).