Town fell to defeat on their return to Portman Road as a Sebastien Haller hat-trick gave Premier League West Ham the victory.
Haller notched his first of the afternoon in controversial fashion at the end of a fast-paced first half.
Four goals inside five second half minutes was the deciding period of the game, Freddie Sears’ goal for Town being sandwiched by Haller’s second and third goals alongside a Tomas Soucek header.
An excellent recovering tackle from Luke Chambers prevented the visitors from opening the scoring on six minutes after Andriy Yarmolenko looked to be in one-on-one with Tomas Holy.
Gwion Edwards played Drinan in behind five minutes later after Flynn Downes had won the ball back inside the Hammers’ half but Darren Randolph comfortably saved his effort from a tight angle.
Some fast-paced link up play from Sears and Stephen Ward then released Teddy Bishop inside the box but the latter couldn’t find a supporting player with his attempted pull back.
Haller should have opened the scoring less than a minute later but, after cutting onto his left foot inside the box, fired straight at Holy.
Downes called Randolph into action with just over 30 minutes played, the midfielder’s effort from distance having to be tipped around the post.
Haller was denied by Holy once again after getting in behind, the Czech goalkeeper parrying away the striker’s low drive from inside the box.
Downes’ pressing led to another chance for Town but Bishop blazed over the bar from outside of the box when passing may have been the better option.
West Ham broke the deadlock a minute before the break, Grady Diangana being adjudged to have kept the ball in play before pulling back for Haller to tap in from inside the six yard box.
A combination of Holy and the post stopped Yarmolenko from doubling the lead eight minutes after the break.
The Hammers did find the net for a second time upon the hour mark though, Diangana and Haller once again combining for the latter to smash into the roof of Holy's goal from close range.
Sears instantly pulled a goal back against his former club, finishing into the bottom corner after a marauding run from substitute Emyr Huws.
Two more quick-fire goals put the game to bed for West Ham, Soucek heading in at the far post before Haller completed his hat-trick a minute later.
Blues continued to push for a way back into the game but couldn't find the break through as Jon Nolan and Ben Folami were both denied by Randolph in the closing stages.
Town: Holy (Cornell 74), Donacien, Chambers (Ndaba 74), Nsiala, Ward (Smith 74), Dozzell (Huw’s 59), Downes (Nolan 59), Bishop (Judge 59), Sears (Folami 83), Drinan, Edwards (El Mizouni 38).
West Ham: Randolph, Coventry, Cresswell, Balbuena, Alese (Cardoso 56), Soucek (Kemp 74), Yarmolenko, Anderson (Odubeko 81), Haller, Wilshere, Diangana (Lewis 74).
Subs: Roberto.