Full-time from Playford Road
Justin Skinner's charges came up against a strong Ipswich side that included first-teamers Teddy Bishop, Leon Best, Luke Varney, Conor Grant and Paul Digby in their starting line-up.
It was Millwall, however, who created the first chance of the game after eight minutes when Harry Smith's looping effort was hacked off the line by Town's Chris Smith.
Ipswich went close themselves, but striker Best couldn't quite get a clear connection on the ball after Varney had slipped a pass through to his team-mate in a central position, and the danger was cleared.
Back came The Lions, and Eze Ebuzoeme was unlucky not to break the deadlock with a sizzling 20-yard strike that hit the stanchion behind the goal moments before Best had an effort well saved by Tim Brown in the Millwall goal as the sides traded scoring opportunities.
Varney glanced a Conor Grant free-kick narrowly wide and then Lewis White was denied by an excellent save from home keeper Jacob Marsden, who tipped his powerful effort over the bar.
Ipswich got their noses in front four minutes before the break courtesy of a predator's goal from Best, who just managed to squeeze a shot home at the near post from close in.
It could have been two just 60 seconds later, but Varney's acrobatic overhead kick flashed just wide of the upright from a Best cross.
Town's goal-scorer Best came off at half-time to be replaced by McLoughlin and the home side started brightly, testing keeper Brown with a Varney shot that was well saved.
Credit to Millwall who simply regrouped and went again - and that positive attitude paid off on 80 minutes when Leighton's shot hit the underside of the bar and was adjudged to have crossed the line to set up a grandstand finish.
Skinner's side prised and probed in search of an equaliser and thought that they had levelled it up at 2-2 when Smith's header looked destined to hit the back of the net, only for Munsden to somehow claw the striker's close-range effort away.
That proved to be the last clear chance for The Lions who although disappointed with the final result, gave their all against a more experienced Ipswich team.
Team: Brown, McNamara, Farrell, Donovan, Bray, Rooney, Saunders-Henry, Ebuzoeme, Smith, Mundle-Smith, White. Subs not used: Green, Jackson, Wicks, Day, Leighton.
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