Helen Morgan claimed victory after a swing of 37.2% saw her win nearly 6,000 more votes than Conservative candidate Neil Shastri-Hurst.
She has since been on a victory rally in Oswestry with former Lib Dem leader Tim Farron.
The jubilation came after the votes were counted overnight at Shrewsbury Sports Village with the eye's of the country watching.
Boris Johnson has now admitted responsibility for the loss.
We covered the by-election live throughout polling day and night and brought all the reaction live as pressure mounted on Boris Johnson.
Scroll through the live blog below to see how the night unfolded and all the reaction to a famous result.