St Mirren warmed up for their Scottish Premiership play-off against Partick Thistle with a frustrating draw at home to Dundee United.

The visitors scored from their only first-half attack of note, with Max Watters crossing for Zac Sapsford to stab in a smart finish.

The Paisley side, resting several regulars, were lively throughout, with their endeavour finally rewarded when a deflected shot from Jake Young found the net.

Luke Douglas was full of running on his first St Mirren start and the 16-year-old thought he had scored when Dave Richards allowed a shot to go right through him, but an offside flag spared the visiting goalkeeper's blushes.

Earlier, Richards had looked much more assured, tipping away efforts from Douglas and Jayden Richardson, while he also had to push over a fierce strike from Alex Gogic after Sapsford had netted for the 11th time this season.

Douglas slammed a first-time shot wide early in the second half as the hosts continued to dominate.

It looked like a goal would elude the league's lowest scorers until Young's shot from the edge of the penalty area spun off a defender leaving Richards helpless.

Teenager Thomas Falconer drilled a shot against the post as St Mirren finished strongly and a close-range overhead kick from Gogic was blocked during a stoppage-time stramash.

St Mirren go to Firhill for the first leg of their play-off final on Thursday, with the second game in front of their own fans on Monday.

Those supporters might be feeling a bit better about the nerve-wracking contest given this bright display, following on from Tuesday's 2-0 win away to Aberdeen.

Only scoring once will be a concern though, as the Buddies end the regular season with just 30 goals from their 38 outings.

Liam Donnelly, Richard King, Jacob Devaney, Killian Phillips and Mikael Mandron were among those omitted from the starting XI before the showdown with Thistle.

Douglas took his opportunity with both hands and was a real buzzbomb presence, full of running and clever movement.

He was given a rousing ovation when replaced late on and could be a very handy option from the bench in the vital double-header to come.

The other worry for St Mirren is Thistle will be far more motivated than United, who turned in a rather half-hearted display.

The visitors had seventh place wrapped up prior to kick-off and end the campaign with only 10 wins after a 15th draw.

Jim Goodwin's team began the post-split fixtures in style with a 3-0 derby victory at Tannadice but a ho-hum season has been allowed to fizzle out with a four-game winless run.

St Mirren interim manager Craig McLeish: "First half had a bit of an end-of-season feel to it. Second half, I thought there was more energy, more intensity, we moved the ball quicker.

"We asked for a positive performance to build confidence for the games we've got and I thought we got that. Now we need to do everything we can to try and stay in the league."

Dundee United manager Jim Goodwin: "We are disappointed with the position we find ourselves in, but the campaign as a whole has not been a disaster. We were caught in that little bit of limbo, not being able to catch those above us and never involved in the relegation battle.

"It's clear where the problems have been for us, we've conceded far too many goals. Three goalkeepers across the season is not ideal."