Jim Magilton wanted his side to hit the ground running this season but the Town boss couldn't have expected Blues to have been three goals up inside the first 25 minutes.
Alan Lee set Town on the way in the first minute, scoring from the penalty spot after Pablo Counago had been pulled back inside the box by Lee Bullen.
Counago, back at Portman Road for a second spell after two years at Malaga, was at the centre of everything good about Blues' play and his deft flick sent Lee clear on 10 minutes, the striker's cross brilliantly volleyed home by Gary Roberts.
Town swarmed all over the Owls, Jon Walters denied by Lee Grant in the Wednesday goals, Counago then blocked by Bullen's challenge.
Franny Jeffers' every touch was greeted by the expected boos and the Owls' new signing was thwarted at every turn by Alex Bruce, the defender twice blocking shots.
At the other end Walters' strong run almost found a way to goal before Town did make it three on 24 minutes, Counago releasing Lee whose speculative shot from the angle bounced over Grant's dive.
Jason De Vos covered well as Steve Watson looked to get in on a Marcus Tudgay pass, the midfielder going down in the box but referee Richard Beeby waved away the penalty appeals.
Bruce sent a header just over the bar from an Owen Garvan free-kick, Counago did brilliantly again to set up Walters whose shot was blocked, then Bruce went close with another header.
Wednesday had few openings but Tudgay should have scored when Jeffers' shot fell into his path, the striker blazing wide then Bruce did brilliantly to clear from Jeffers on the goalline.
Wednesday made a change at the break, Kenny Lunt coming on for Bullen, the midfielder immediately picking up a booking for a foul on Garvan.
Counago got the goal he fully deserved on the hour, Lee winning the ball on the right and releasing Walters whose cross was stroked into the net by the Spaniard.
Neil Alexander, making his Town debut after his summer move, dealt with everything he had to do comfortably, saving well from Glenn Whelan, then cutting out the danger from a Chris Brunt cross.
Another flying Town move almost saw a fifth goal, Lee lunging at Garvan's cross and seeing the ball divert inches wide of the visitors' goal.
Jeffers and Counago were both replaced on 73 minutes, to contrasting receptions from the home fans, the two Clarkes coming on - Billy for Blues, Leon for the Owls. Wade Small soon joining the action as well for Jermaine Johnson.
Sylvain Legwinski came on for Tommy Miller for the last seven minutes as Town wound down the clock but not quick enough for Wednesday to grab a consolation goal, Clarke forcing the ball in from six yards after Bruce had cleared off the line.
Town: Alexander, Wright, De Vos, Bruce, Harding, Walters, Garvan, T.Miller (Legwinski 83), Roberts, Lee (Haynes 66), Counago (Clarke 73). Subs not used: Supple, Wilnis.
Wednesday: Grant, Simek, Bullen (Lunt 46), Wood, Gilbert, Johnson (Small 76), Whelan, Watson, Brunt, Jeffers (Clarke 73), Tudgay. Subs not used: Hinds, Burch. Booked: Simek, Lunt.
Att: 23,099


















