The Central Division 1 outsiders started survived early scares in this first round tie on Saturday when Robert Sloan and Ross Philp had early efforts before on 10 minutes visiting keeper Kieran Dougan pulled off an excellent stop from a Fraser Keast drive.
Bellshill then shocked the hosts when they took the lead on the quarter hour when Declan Brown crossed for Kyle Robertson who volleyed home.
United then went close to levelling it up but a Marty Wright header was brilliantly tipped onto the bar and from the rebound Keast saw his header clip the bar.
The visitors almost extended their lead on the half hour when Lee Nichol linked with Brown before seeing his shot go inches wide with the keeper beaten.
Bo’ness then levelled through Wright who found the net with a decent finish and then just before the break United went ahead after a good jinking run from Wright saw him square it to Keast who tucked the ball into the net.
Bo’ness had the first opportunity after the interval when Wright released Philp who shot narrowly wide.
Keast then played in Wright with a good ball and the forward saw his drive saved by Dougan who was having an excellent game.
Bo’ness then got their third just before the hour when Sloan stepped up and curled a 25 yard free-kick into the top corner.
Keast went close to sealing it but Bellshill were to get back into it when Scott Ritchie smacked his clearance off Robertson with the ball going to Brown who finished calmly.
Bo’ness were beginning to look very nervous with misplaced passes becoming more common and the visitors had shots from Nichol, Brown and Robertson as they pressed for an equaliser.
United had a chance to clinch it but Nicky Walker, playing his final game for the club, saw his shot saved under pressure before Bellshill tied it up when Will Snowdon was caught inpossession by Richard Kane and the ball came to Robertson who scored.
United had a chance to win it in injury time but Snowdon blasted over and nobody can grudge Bellshill the opportunity of a replay.