Barnet take a one-goal advantage into Monday's play-off semi-final at Gay Meadow thanks to a last-gasp winner from Simon Clist.
It was an inspired substitution by Barnet's Paul Fairclough who brought Clist on as a late replacement.
He said: "I felt I needed to make a change, sometimes it comes off. Shrewsbury had a magnificent first half, but we doubled our passion in the second and it was a superb performance." His opposite number Jimmy Quinn was left rueing his side's missed chances but Quinn is confident that the Shrews can turn the tie around.
He said: "I'm very disappointed by the way we conceded the late goal, but we are at home on Monday and there will be 8,000 people cheering for us at Gay Meadow and if we score it will be all to play for." It was Barnet who took the lead in somewhat controversial fashion. Liam Hatch looked to be chasing a lost cause with goalkeeper Scott Howie looking favourite to collect the overhit pass, but Hatch managed to make up ground and poked the ball past Howie.
The keeper made the slightest connection with the striker who tumbled to the ground and referee Mr Green had no hesitation in pointing to the spot.
Ben Strevens converted the spot-kick for his eleventh goal of the season. It proved to be Barnet's only shot of the half as a rampant Shrewsbury laid siege on Barnet's goal only to be denied by some excellent defending by Danny Maddix and Ian Hendon.
The Shrewsbury onslaught was relentless and an equaliser was inevitable. On 37 minutes a goal looked certain as Ryan Lowe crossed for Duane Darby, whose header from three yards looked goalbound but Shane Gore produced an excellent save to keep the ball out of the net.
Three minutes before half-time Shrewsbury were level and it was no less than they deserved. Sam Aiston burst into the Barnet penalty box before unleashing a 20-yard shot which struck Joe Gamble's hand.
Mr Green pointed to the spot for the second time in the evening and Luke Rodgers took responsibility, firing the ball high into the net.
The Bees steadied themselves in the second period and Maddix nearly restored the lead, but his header from three yards sailed over the crossbar.
Barnet did put the ball in the net through Chris Plummer, but his effort was ruled out for a foul.
The game then descended into a succession of ugly tackles with Jamie Tolley, Maddix, Darby and Hendon all receiving bookings.
Then in the third minute of added time, second-half substitute Clist steered in Ismail Yakubu's pass with virtually the last touch of the game.