Barnet delivered a Carabao Cup upset with a 3-1 win at Peterborough.
Jean-Louis Akpa-Akpro opened the scoring for the League Two side and, despite Gwion Edwards' leveller, Mauro Vilnete and a penalty from former Peterborough striker Shaquile Coulthirst won it for the visitors.
Barnet started brightly with David Tutonda hitting the post from 25 yards and Coulthirst having a shot saved by home goalkeeper Jonathan Bond.
Akpa-Akpro then found the roof of the net after 22 minutes following a header across goal by ex-Posh player Ricardo Santos.
Edwards levelled after half an hour, firing in low from 25 yards, but a slick passing move nine minutes later ended with Vilhete finding the corner.
The midfielder's free-kick after 58 minutes was then adjudged to have been handled in the wall by Ryan Tafazolli. Coulthirst stepped up to score the penalty, albeit the ball dribbled in after Bond got a hand to it.
Posh had a good chance to pull a goal back, but Barnet goalkeeper Jamie Stephens turned Tafazolli's header onto the bar.