St Mirren started on the front foot against United and had the visitors pinned back in the opening exchanges, with Dylan Connolly causing problems down the right flank, but were unable to threaten Ross Doohan's goal.

United went close to opening the scoring after 13 minutes when Logan Chalmers and Lawrence Shankland combined inside the penalty area. Shankland backheeled into Chalmers' path but Ryan Flynn slid in to make a crucial intervention and deflect his shot just wide.

St Mirren had a huge shout for a penalty after 27 minutes when Eamonn Brophy tumbled in the box. Brophy latched onto Lee Erwin's flick on and was in on goal. He hesitated rather than take a shot and then probed the ball past Doohan and hit the deck as the keeper dived at his feet but referee Euan Anderson waved away the penalty appeals.

Shankland forced a save from Jak Alnwick with a header from Robson's cross.

Four minutes before the interval St Mirren went close as Jay Henderson clipped in a cross from the left flank that Jamie McGrath got onto the end of but he sent his header just wide.

Just after the interval Shankland played a neat flick onto the path of Chalmers and he let fly from the edge of the box but Alnwick was well placed to pull off the save.

St Mirren then went close on a couple of occasions but Doohan produced a couple of smart saves to deny them.

When Connolly got in down the right flank his cross deflected off Jeando Fuchs and looked to be creeping in at the near post but Doohan reacted well to get down and turn it round for a corner.

Then Brophy let fly with a powerful drive from 25-yards that Doohan managed to fingertip it over the crossbar.

St Mirren went close again when substitutes Cameron MacPherson and Kyle McAllister combined as the played a slick one-two and MacPherson then curled a shot just wide.

Dundee United were reduced to 10 men after 71 minutes when Robson was shown a straight red card. The youngster made a rash challenge on McAllister as he tried to win back possession, stamping on his ankle, and referee Anderson had no hesitation in giving him his marching orders.

United threatened late on but substitute Marc McNulty opted to try to tee up one of his team-mates rather than shoot himself and St Mirren survived.