Two second-half goals from Stevenage ended Town’s stay in the Capital One cup at the first round stage.
Blues had chances, Christophe Berra seeing an early header cleared off the line but a penalty from Filipe Morais after Luke Hyam had fouled Oumare Tounkara and a well worked strike from Jordan Burrow gave Stevenage the victory.
Boro were forced into a change before kick-off with ‘keeper Chris Day pulling up in the warm-up, Steve Arnold coming in. For Town, Paul Taylor made his first start under Mick McCarthy in one of six changes to the team that performed so well at Reading at the weekend.
Frank Nouble, one of those changes, was prominent early on, his shot cannoning away for a corner, Berra seeing his header cleared off the line by Sam Wedgbury.
The League One club responded just before the quarter hour, Tounkara heading over six yards out from Luke Freeman’s cross.
Former Arsenal winger Freeman provided a threat down the right for Stevenage and his cross was cleared by Luke Chambers as Tounkara threatened to pounce at the far post.
Paul Anderson, making his first start for Blues since joining from Bristol City in the summer, escaped down the flank but saw his cross put behind for a corner, Taylor firing wide seconds later after trying his luck from 25 yards.
Town suffered a blow when Jay Tabb was forced off on the half hour, the midfielder clearly in discomfort with what looked a rib injury, Carlos Edwards the replacement.
Taylor had Arnold sprawling across his goal just before the break, while at the other a Greg Tansey pass fed Morais, who brought a low save from Dean Gerken.
Edwards was inches away from converting a Luke Hyam cross, then Taylor brought a save from Arnold in the nearest Town came to breaking the deadlock in an evenly contested first-half.
Freeman tested Gerken inside the first minute of the restart before Stevenage were handed a penalty on 51 minutes, Hyam judged to have caught Tounkara and Morais expertly converting from the spot.
Town made a double change soon after, David McGoldrick and Daryl Murphy replacing Taylor and Nouble, McGoldrick immediately in the action with a right foot effort pushed away by Arnold in front of the 1000 strong Blue Army.
Town pressed for an equaliser, Murphy was crowded out inside the box then Anderson saw a snap shot go inches wide.
Gerken had to be quick off his line to deny Tounkara after a long ball caught out Berra before Stevenage doubled their advantage on 76 minutes, Simon Heslop beat the Town defence with a slick pass, Robin Shroot crossed and Burrow did the rest from close range.
McGoldrick rallied for Blues, Arnold equal to the task with save to his left, the ‘keeper then denying Tommy Smith with a terrific save as Town failed to get a lifeline that a goal would bring.