The Dons bowed out of the Johnstone’s Paint Trophy at the second-round stage following a 3-2 defeat to AFC Wimbledon at stadiummk.
The same back four that ended the success over Yeovil Town started the clash with AFC Wimbledon, while Tom Hitchcock started in the No.10 role.
Karl Robinson’s men got off to the perfect start when, after just two minutes, Powell latched on to a poor back-pass, rounded keeper James O’Shea and slotted the ball into an empty net to give the Dons early lead.
Powell almost turned provider for Afobe shortly afterwards but the latter’s goal-bound effort was blocked as the men from MK1 looked to increase their advantage.
Ade Azeez flashed a header just past the post from a free-kick just past the midway point of the first half while, at the other end, referee Tim Robinson waved away strong appeals for a penalty on 25 minutes despite Powell’s cross seeming to strike the hand of an AFC Wimbledon defender.
The visitors were level a minute later when Jack Smith crossed for Azeez, who bundled the ball home from inside the Dons’ six-yard box.
Both sides missed reasonable chances in the 29th minute, with Tom Beere flashing a shot over top for AFC Wimbledon from 15 yards before Benik Afobe fired wide from the penalty spot.
Afobe made no mistake on 41 minutes, and in the process bagged his 11th of the season. After making the most of a second poor back-pass by AFC Wimbledon, he was initially denied by Shea but, after Powell threaded the rebound back to him, he beat two defenders on the line with his low shot.
It could have been 3-1 as the half-time whistle approached when Hitchcock beat the offside trap. The striker was thwarted by Shea but the loose ball fell for Dean Bowditch, who was denied on the line by an AFC Wimbledon defender.
However, it was almost 2-2 in the early stages of the second half but Kyle McFadzean was in the right place at the right time to deflect Azeez’s effort over the top.
The Dons resumed control as the game ticked towards the hour mark, but there was little in the way of goalmouth action.
New recruit Carl Baker came on for his home debut in the 66th minute when he replaced Samir Carruthers, but he and his team-mates found themselves pegged back two minutes later when, out of nothing, AFC Wimbledon substitute Sean Rigg fired into the net from 18 yards.
Fellow substitute Akinfenwa headed a golden chance over the top when well placed shortly afterwards as Neal Ardley’s men threatened to take the lead, something they came even closer to doing when David Martin clawed away Rigg’s header on 75 minutes.
It was Shea’s chance to shine two minutes later when he expertly pushed away Afobe’s close-range effort while, at the other end, Akinfenwa scooped over another good chance.
By this time, it was end-to-end stuff and the next foray forward saw Afobe drive a shot inches wide of the bottom left-hand corner.
However, it was AFC Wimbledon who took the lead for the first time on the night on 81 minutes when Akinfenwa slotted Rigg’s left-wing delivery past Martin from 12 yards.
Baker, who was impressing alongside Darren Potter in midfield, tested Shea with a curling effort on 83 minutes, prior to Martin keeping the Dons in the tie with two saves in quick succession to deny Smith and Dannie Bulman.
The Dons were unable to turn some late pressure into an equaliser and they exited the competition they won in 2008.
Starting XI: Martin; Randall, Spence, McFadzean, Lewington (c); Potter, Carruthers (Baker 66); Powell, Hitchcock, Bowditch; Afobe.
Subs: McLoughlin, Hickford, Tilney, Rasulo.
Goals: Powell (2), Afobe (41).
Bookings: Carruthers, Randall, Powell.
Attendance: 4,407 (214 away).