A second half Darren Bent goal gave Town their first ever play-off semi-final first leg win, against West Ham at Portman Road. The Blues had much the better of the game and will be confident going into Tuesday's second leg at Upton Park.
Town lined-up with an increasingly familiar look about them but with Richard Naylor coming in alongside Darren Bent up front in place of Shefki Kuqi. Tommy Miller was fit enough to take his place in midfield, while Chris Bart-Williams returned to the bench.
After a first minute flurry from West Ham, Miller hit the first serious shot of the game but went high and wide. Soon after, a Darren Bent effort was blocked by Tomas Repka after a Blues' corner.
Jermaine Wright had a strike stopped, this time by Christian Dailly, in the seventh minute. Ian Westlake went closer with a shot which went just by Stephen Bywater's post after a corner on the right.
The Blues were well and truly in control of the game, with few signs of the nervousness which was so evident against Cardiff last weekend.
West Ham are always a threat on the break and ex-Town loanee Marlon Harewood had the ball in the net in the 12th minute, however, the linesman's flag had gone up earlier for a foul.
Harewood, a dramatic flop in his short spell with Town in 1999, went close a minute later when he hit a shot into the sidenetting after good work on the right from Bobby Zamora.
Both sides were having chances but the Blues most of the possession, as was the case in both the league games between the teams. Jim Magilton was close with a 25-yard deflected shot which spun just past Bywater's right post.
The West Ham keeper did well to save Darren Bent's header from Jim Magilton's cross in the 14th minute.
Matt Richards was again looking impressive on the left and in the 22nd minute Bywater was forced into action to stop his deflected cross-shot.
There was a scare for the Blues soon after, a swift Connolly break ending with Zamora shooting just wide from the edge of the box.
Town were close to going a goal up just before the half hour. Jermaine Wright played a fine pass for Darren Bent to chase, the striker beating Repka to the ball and taking it past Bywater wide on the left. Bent laid the ball back to Westlake whose shot was stopped on the line by Andy Melville.
Zamora went very near to an opening goal at the other end just a minute later, Zamora shooting across the face of goal and inches away from Kelvin Davis's post.
Kelvin Davis was forced into action for the first time on 33, the keeper saving a Zamora shot after good work on the left from Matthew Etherington.
Town skipper Jim Magilton found his way into referee Mark Clattenburg's book in the 35th minute for catching his former Northern Ireland team-mate Steve Lomas with an arm, a caution which seemed somewhat harsh.
Jermaine Wright came within inches of putting the Blues in front in first half injury time, the midfielder volleying a Jim Magilton corner on the right into the sidenetting from 20 yards.
Town were applauded off at the break by the virtually capacity crowd, having enjoyed much of the best of the game. The only concerns were that none of the chances created had been taken and West Ham's quick breaks, although these had been largely kept under control.
The second half started much as the first had ended. Tommy Miller's shot was blocked on the edge of the box after a fine run — and nutmeg — from Wright on the left.
For the Hammers, Harewood headed over, something Darren Bent replicated at the other end from an Ian Westlake left-wing cross.
Town finally took one of their opportunities in the 57th minute. Jermaine Wright brought the ball forward to the edge of the area and played it to Richard Naylor on his right, who crashed a shot off the bar. The ball hit an unprepared Repka inside the six-yard box before Bent nodded into the net.
Portman Road was as loud as it has been since the building of the new stands, the West Ham fans having been surprisingly quiet throughout.
Bent went looking for a second on the hour, sending a curling 25-yarder over Bywater's crossbar.
Town boss Joe Royle decided to make a change on 76, skipper Jim Magilton this time accepting being switched for Chris Bart-Williams with good grace. Royle probably had one eye on Tuesday's game at Upton Park, with Magilton's legs not as young as they used to be.
Two minutes later Fabian Wilnis picked up a caution for obstructing Etherington on the edge of the Town box. From the freekick Michael Carrick hit a shot which Kelvin Davis punched away for a throw-in.
With seven minutes left on the clock, Shefki Kuqi replaced John McGreal who had gone down after a challenge by sub Brian Deane. McGreal didn't look too seriously hurt as he left the pitch, although he certainly looked less than 100%. Kuqi went up front, Richard Naylor moving into the back three.
On 86 a fan invaded the pitch but order was quickly restored. West Ham enjoyed much of the possession in the later stages as the Blues were happy to sit on their one-goal lead, the whistle going after three minutes of injury time.
A fine display from Town, particularly in the first half, and one which sees them going into the second leg with the lead which manager Joe Royle said he was after.
There were excellent performances throughout the side with Jermaine Wright and Jim Magilton particularly outstanding in midfield, Matt Richards having a fine game at the back and Kelvin Davis solid in goal.
Town might have scored more than just the single goal, however, their away form this season has been as good if not better than at Portman Road. A similar display at Upton Park on Tuesday should seal a place at the Millennium Stadium.
Town: Davis, Wilnis, Richards, McGreal (Kuqi 83), Elliott, Magilton (Bart-Williams 76), Miller, Wright, Westlake, Bent, Naylor.