Lanark let themselves and their fans down with an inept display against Gartcairn at Moor Park on Saturday.
Needing a win which would have virtually guaranteed them promotion, they failed to match the visitors in all aspects, especially in the first half.
Former Lanark player John Henderson opened the scoring on 13 minutes when he scored from a low cross into the box.
On 34 minutes another ex-United player Jordan Love added goal number two with a header from close range.
The visitor’s keeper Anton Nugent then produced a very good save to turn a shot from David O’Donnell over the bar.
Two minutes into the second half United fell three behind when Chris Paterson headed home a right wing corner.
Lanark picked up after this and on 70 minutes Ronan Kearney finished off an excellent move between D.O’Donnell and Kieran McGurk with a powerful left foot shot into the roof of the net.
Both sides competed well in the closing stages but there were no more goals in a disappointing game for the Moor Park men.
East Kilbride Thistle are now the only team which can catch United for the third promotion spot but to do so they will need to amass seven points from their last three games.
Lanark United manager John Brogan was disappointed at his team’s performance, saying: ‘‘We were well beaten, especially in the first half, our players just did not turn up.’’
On his club’s finish in third spot and the chance of promotion, he added: ‘‘We have had a great season and while we are in third we are by no means promoted yet.
‘‘East Kilbride still have a chance to take third place and it will be up to the other clubs, Gartcairn, Dunipace and Royal Albert to turn up and do us a favour.’’