Cole Stockton’s 22nd-minute goal has given Morecambe a 1-0 half-time lead over the Blues at half-time at Portman Road.
Eight players were handed their Blues debuts the Gamechanger 20 and Paul Cook eras got under way in earnest.
Vaclav Hladky was in goal with Matt Penney at left-back, while Kane Vincent-Young at right-back and centre-halves Toto Nsiala and Luke Woolfenden, the only player who was involved in the final day game against Fleetwood, were the only players starting who were at the club last season.
Lee Evans skippered in central midfield alongside Rekeem Harper with Scott Fraser on the left and Wes Burns on the right. Conor Chaplin was behind lone striker Joe Pigott.
For Morecambe, ex-Blues loanee Toumani Diagouraga and academy product Shane McLoughlin both started as they handed six players debuts after a summer personnel turnaround of their own.
The 20,000-plus Portman Road crowd making their return after 17 months had already been in fine voice before manager Paul Cook appeared to rapturous applause four minutes prior to the scheduled kick-off time before taking his place in the dugout.
The volume increased significantly when the players made their way out of the tunnel and lined-up for the handshakes across the halfway line.
After a minute’s applause in tribute to legendary Blues striker Paul Mariner, who died last month aged 68, the game got under way with the crowd continuing to make themselves heard.
But it was the Shrimps who made all the early running, winning a corner, from which Ryan Cooney spectacularly air-kicked after the ball was played to him just outside the area.
On seven, Morecambe keeper Kyle Letheren had to rush off his line quickly to clear after a defender deflected a through ball towards him with Burns chasing into the area.
Three minutes later, Fraser was bundled over by Diagouraga five yards outside the penalty area to the left. Evans took the kick and caused the first ‘Oooo’ of the afternoon from the fans as his shot flew narrowly past Letheren’s right post.
Town began to get more into the game and on 13 Vincent-Young was felled by Liam Gibson as he broke away down the right but Fraser’s free-kick came to nothing.
The Blues were gaining confidence and were starting to find some fluency with the noise of the fans behind them, and in the 19th minute Pigott wasn’t too far away from opening his account when he flicked a stooping near-post header across goal from Fraser’s corner from the right onto the roof of the net.
However, it was the Shrimps who would take the lead in the 22nd minute with their first goal in League One.
Vincent-Young’s poor clearance found Cole Stockton, who brought the ball into the area and to the right unchallenged with the Town backline standing off him before slipping past the advancing Hladky.
It was a dreadful goal to concede from a defensive perspective but one which will live long in the memory for Stockton and the travelling Morecambe fans.
Town set about getting back on terms and didn’t look unduly affected by going behind - the team of the last few seasons having been one which often reacted badly to adversity - and in the 28th minute Nsiala nodded wide at the far post under pressure from a Fraser corner from the right.
However, Stockton wasn’t too far away from a second on the half hour when, following a neat move, he curled a low shot past Hladky’s left post from 25 yards with the ball, according to referee Craig Hicks, having taken a deflection on the way.
Morecambe were forced into a sub in the 33rd minute when Ryan Delaney, who trained with Town during a pre-season trip to Ireland in 2016, was replaced by Sam Lavelle.
Two minutes later, Nsiala pulled up as he ran down the touchline holding his hamstring and dropped to the turf. With new signing George Edmundson not fit and not on the bench, and Corrie Ndaba having played for the U23s this morning, Janoi Donacien took over in his less favoured centre-half role.
Almost immediately after the change, Penney was sent away in space on the left of the box and struck a shot into the side-netting, reinvigorating the support.
As the game moved into injury time, a Morecambe free-kick on the left dropped to Arthur Gnahoua just inside the box but the Frenchman’s effort looped well into the Sir Bobby Robson Stand.
The Blues built up a head of steam in the final moments of the half and put the visitors under pressure. A Vincent-Young shot blocked, then a cross came in from the left from Penney, before Burns sent over a dangerous low ball from the right which flashed along the six-yard line with no one able to get a touch.
There was applause at the whistle despite Town being behind. It had been a patchy half from the Blues. After a slow start, they had started to gain control of the game when Morecambe scored a goal which was a bit of a mess from a Town perspective.
Town hadn’t managed a shot on target but in the final couple of minutes before the break they began to put the Lancastrians under pressure, something they will need to continue once the second half gets under way.
Town: Hladky, Vincent-Young, Nsiala (Donacien 38), Woolfenden, Penney, Harper, Evans (c), Burns, Fraser, Chaplin, Pigott. Subs: Holy, Norwood, Barry, Dobra, El Mizouni, Bonne, Donacien.
Morecambe: Letheren, O’Connor, McDonald, Diagouraga, Stockton, Delaney (Lavelle 33), McLoughlin, Cooney, Gibson, Gnahoua, McCalmont. Subs: Andresson, Mellor, Leigh, Jones, Ayunga, Phillips. Referee: Craig Hicks (Surrey).