Town and Bolton remain level at 0-0 at the break but with the visitors having had the better chances.
Blues boss Mick McCarthy named an unchanged team aside from Bartosz Bialkowski replacing Dean Gerken in goal. McCarthy had previously said that Gerken wouldn’t be risked having been knocked unconscious at Middlesbrough on Saturday.
Ipswich-born former Northgate pupil and one-time Blue Liam Trotter started in midfield for the visitors, who made a late change on their bench with Kaiyne Woolery replacing Adam Le Fondre.
Town began the game on top, Jonny Parr shooting over after a corner had been cleared to him just outside the area in the seventh minute.
Bolton threatened for the first time two minutes later when Craig Davies played in Eidur Gudjohnsen inside the area but the Icelander was out-muscled by Tyrone Mings. Moments later, Giles Coke struck a 20-yard effort which Bialkowski rather unnecessarily punched away.
The Blues ought to have gone in front in the 16th minute when Freddie Sears stole the ball from Tim Ream and went through one-on-one with keeper Ben Amos, who stood up well and blocked.
On 22 Cole Skuse picked up the game’s first yellow card for a trip on the lively Rochinha as the on-loan Benfica midfielder broke into the Town half.
Bolton started to get on top, Trotter shooting well wide in the 25th minute before Davies cut a dangerous ball across from the left but too far in front of Josh Vela at the far post.
Just before the half hour, Mings made a strong run through the middle from inside his own half before feeding Sears to his left. The ex-Colchester man crossed and the left-back flicked across goal and wide.
Bolton immediately broke, Christophe Berra and Tommy Smith eventually dispossessing Gudjohnsen before Rochinha slipped and Skuse cleared the danger.
A previously subdued Portman Road was starting to wake up and on 31 the Blues went close again, Berra heading a freekick across goal from the far post and Smith diverting a looping ball back into the six-yard area but with no Blue shirt present.
With the action swinging from one end to the other in a very open half, Bolton twice went close within a minute.
First Bialkowski palmed Davies’s shot from the edge of the box out to Vela, who cut back to Gudjohnsen, but the veteran’s effort was deflected wide by Mings.
From the corner, the Trotters went even nearer, Dorian Dervite nodding down to Ream in the six-yard box. The American international worked himself space to shoot but saw Parr block his weak effort on the line, the ball inadvertently bouncing up off the Norwegian’s arm before he cleared.
Tabb broke through from midfield in the 38th minute but could only shoot straight at Amos, who claimed comfortably.
But it was the visitors who were continuing to look the more threatening side with debutant Rochinha’s running their main danger.
In the 41st minute the Portuguese brought the ball forward from deep at pace past a number of defenders, exchanged passes with Davies but shot just wide of Bialkowski’s left post when he seemed certain to score. It was a major let-off for the Blues. Neither side threatened again before referee Fred Graham brought the half to a close.
Bolton will feel they should have been ahead at the end of an open half having come closest to scoring through Ream and the impressive Rochinha. Town had had chances but the better opportunities had been the visitors’.
Town: Bialkowski, Chambers (c), Mings, Berra, Smith, Skuse, Bishop, Parr, Tabb, Murphy, Sears. Subs: Kenny, Clarke, Anderson, Chaplow, Bru, Varney, Wood.
Bolton: Amos, Vela, Mills, Dervite, Ream, Trotter, Coke, Walker, Rochinha, Gudjohnsen, C Davies. Subs: Bogdan, Moxey, Woolery, Hall, Twardzik, Bannan, Threlkeld. Referee: Fred Graham (Essex).