Colchester were dumped out of the FA Cup by League Two opposition for the second successive year as Peterborough claimed a comfortable win at Layer Road.
Manager Geraint Williams has never beaten a side from the bottom division in cup competition during his Colchester reign and his side never looked like ending that hoodoo as they were outplayed by Darren Ferguson's promotion chasers.
Aaron Mclean opened the scoring early in the first half before Teddy Sheringham equalised from the spot but goals from George Boyd and Charlie Lee sealed the match in the second half.
Both managers made just one change to the teams that both secured 2-1 wins on New Year's Day with Sheringham coming in up front for Colchester in place of Clive Platt and Jeff Hughes replacing the suspended Jamie Day for Peterborough.
And Hughes made an immediate impact as his corner led to the opener after just four minutes.
He whipped in a good ball from the left side and Mclean was on hand to stoop low and head home for his 20th goal of the season from six yards.
Boyd then scuffed a shot wide before the Us had their best chance as Mark Tyler saved well with his legs as Mark Yeates tried to place a shot past him.
Mclean should have had his second when bringing a good save from Dean Gerken and the striker had another golden chance just after the half-hour as Chris Whelpdale supplied a good cross from the left which Mclean headed against the post.
But Colchester were level two minutes before the break when Whelpdale nudged Kevin Lisbie in the back in the area and the referee had no hesitation in pointing to the spot.
Despite Lisbie scoring from 12 yards against Charlton last time out it was Sheringham who took the spot-kick - and he tucked it away for his fourth goal of the season.
The Essex side were not level for long however as Posh regained the lead within a minute of the restart through Boyd.
Whelpdale threaded a ball to Lee on the right who supplied the cross for Boyd to make up for his earlier miss and volley home left-footed from the edge of the area, giving Gerken no chance.
Sheringham nearly had Colchester level again just seven minutes later as Yeates supplied a cross which found the veteran frontman, who had timed his run to perfection, but he poked his effort wide.
Yeates was on hand again in the 71st minute with a surging run and cross which found substitute Karl Duguid who skewed his shot well over the crossbar when he should have done far better.
And he was made to regret that miss just two minutes later as a corner at the other end from Hughes was met by the head of Lee to seal Peterborough's place in round four.
Teams:
Colchester Gerken, White, Baldwin, Virgo, Elokobi, Yeates, Guttridge, Jackson, McLeod (Duguid 60), Lisbie, Sheringham (Guy 73).
Subs Not Used: Cousins, Izzet, Balogh.
Goals: Sheringham 43 pen.
Peterborough Tyler, Newton, Morgan, Charnock, Hughes, Whelpdale (Gnakpa 86), Lee, Hyde, Boyd, Mclean, Mackail-Smith (Howe 89).
Subs Not Used: Low, Keates, Strachan.
Booked: Whelpdale, Morgan.
Goals: Mclean 4, Boyd 46, Lee 73.
Att: 4,003
Ref: Andre Marriner (W Midlands).