In what was a competitive clash between two Midlands rivals, it looked set to become the first goalless stalemate of the top-flight season until the midfielder picked up the ball from range in the 90th minute and drove home a peach, claiming yet another three points for the Villans.
Story of the Match
Quiet first period
Chances were at a premium in the opening stages of the match as both sides got a feel for the ball but Leicester did manage to force a few stops from Emi Martinez through Ayoze Perez, Timothy Castagne and Kelechi Iheanacho.
One of Villa's best chances of the opening period was predictably the work of Jack Grealish as he combined with Matt Targett and then rolled a low ball into the path of Trezeguet. Just as it looked like the Egyptian was going to strike the opening blow, his shot skidded just off target.
Barkely steals victory late on
Dean Smith's side improved after the break and really should have taken the lead minutes after the restart but Ezri Konsa couldn't quite nudge his header home from Grealish's corner. Youri Tielemans was the next to go close as his deflected shot was well parried by Martinez.
Chances continued to come and go throughout the second-half as Douglas Luiz and Ollie Watkins saw powerful drives caught by Foxes' keeper Kasper Schmeichel.
Just as it looked like the game was destined to end goalless, Villa finally got their goal. Breaking up-field, on loan Chelsea man Barkley found plenty of space from range and drove an absolutely stunning strike into the bottom corner of the Leicester net, claiming another goal and yet another three points for Smith's men who now sit second.
Meanwhile, it's now two defeats in as many games for Leicester as they turn their attention to their UEFA Europa League campaign.
Recruitment paying off for Villa
Following their poor campaign last season, a lot of recruitment was required for Aston Villa and it seems to have certainly paid off and was a big reason behind this win. Matty Cash looked increasingly composed at right-back, with Emi Martinez also keeping Leicester at bay.
That doesn't even mention Ross Barkley who already looks to be a shrewd signing from Chelsea after back-to-back strikes.
A different type of victory?
It was always going to be a tough ask for Villa to match the performance levels of their 7-2 victory against Liverpool a fortnight ago fand for large swaths of the game in the East Midlands, they struggled to create any real chances of note.
They were not quite at their fizzing best but that mattered not as they secured yet another victory. This time, their defensive abilities were given a thorough examination as they stayed compact and determined to keep Leicester quiet. Barkley then struck exactly when it mattered to secure a hard-fought win - quite the opposite to two weeks ago.
Worrying signs for Leicester?
Following three wins in a row to start the season, Leicester have now suffered back-to-back defeats at home against sides they would otherwise have expected to beat in Aston Villa and West Ham United.
Even more worryingly, in both matches they have failed to really threaten the opposition to a great extent which will concern Brendan Rodgers. He really has to find a way to break down visiting teams if the Foxes are to avoid another dramatic downturn of form.