Ben Herd's 90th minute leveller brought Shrewsbury a deserved share of the spoils just when the Underhill side looked likely to claim victory and take the points back to north London.
By this stage both sides had lost a player to a straight red card offence – Shrewsbury's Under-21 Welsh midfield man Jamie Tolley having been ordered off in the 65th minute for a foul on Simon King with Barnet defender Ismail Yakubu given his marching orders for crashing into Neil Ashton with nine minutes left.
When the sides last met 16 months ago in a Conference play-off semi-final the match went to a penalty shoot-out with Shrewsbury finally winning the day. On this occasion a mini penalty shoot-out occurred with Colin McMenimen putting the home side ahead with his fifth goal of the season on 12 minutes after Shrews' skipper Kevin Sharp had been brought down by King.
But 90 seconds later Barnet were on level terms – themselves scoring with a penalty with Nicky Bailey firing home from the spot after Herd had handled a cross from the same player.
Both sides then had chances to establish the lead, but it was the visitors who eventually took the lead, when a fierce shot from Louis Soares beat teenage Shrewsbury goalkeeper Joe Hart at his near post in the 31st minute.
After the break Hart came to his side's rescue, twice saving well from Dean Sinclair, but Shrewsbury saw their bid to salvage a point made even harder against a well-organised Barnet side, when Tolley was dismissed shortly after the hour.
Barnet skipper Guiliano Grazioli missed a good chance to seal victory for his side with 15 minutes remaining, although at the other end it needed a fine diving stop from Ross Flitney to keep out a low drive from Herd.
With nine minutes left the visitors were also down to ten men with the dismissal of Yakubu for a rash challenge on Ashton – and there was to be one final twist in the enthralling contest when Herd nodded home a close range equaliser at the death.