St Johnstone took a huge step towards securing cinch Premiership safety with a hard-fought 1-0 win over 10-man Dundee United at McDiarmid Park.

Saints captain Liam Gordon scored the opener just before the break, while United had Charlie Mulgrew sent off for bringing down Melker Hallberg as he went through on goal.

The Perth side’s first win since February and their first home victory since November sees them move five points clear of danger, while the visitors – who hit the goalframe through Steven Fletcher in stoppage time – remain just a point above Ross County as their three-game winning streak came to an end.

St Johnstone interim boss Steven MacLean had made three changes following his side’s 1-1 draw with Hibernian, with James Brown, Hallberg and Graham Carey all coming in to start.

United manager Jim Goodwin named an unchanged side for a third straight match.

Spurred on by a raucous away support, the visitors started brightly and they had four shots blocked in the first two minutes in a frantic opening to the game.

Fletcher then stung the palms of Remi Matthews in the 12th minute before Ian Harkes headed straight at the home goalkeeper when well placed.

United were dominant and they almost took the lead in the 21st minute when Ilmari Niskanen was released by Harkes but his shot was deflected wide as he opted to chop back inside.

St Johnstone eventually came to life around the half-hour mark and United keeper Mark Birighitti was forced to get down low to keep out Adam Montgomery’s cross that had flicked off Loick Oyina.

Birighitti then produced an even better save moments later to tip over Carey’s rising angled shot from just inside the box.

Despite their slow start Saints were now in the ascendancy, and they took a crucial lead two minutes before the break.

After United failed to clear a long throw-in, Stevie May’s miskick landed kindly at the feet of Gordon, who was able to steer the ball in off a post from eight yards out.

The second half was a fairly even contest before a moment of drama on the hour mark saw the away side reduced to 10 men.

Hallberg latched on to Carey’s neat ball over the top and he got his toe to the ball before Mulgrew, who appeared to catch the midfielder with an outstretched boot.

Despite the tackle occurring out wide, referee Alan Muir wasted no time in issuing the red card, with Mulgrew adjudged to have been the last man.

After an open first half, the game became far cagier after the red card, with United struggling to create and the hosts content to hold onto their lead.

Daniel Phillips and Drey Wright both had sights of goal from just outside the box but neither troubled Birighitti.

Saints could have put the game to bed with five minutes to go as Zak Rudden laid the ball off to fellow substitute Theo Bair, who sidefooted over from just inside the box, while Carey also tested Birighitti with a shot from a tight angle.

There was very nearly a late twist deep into stoppage time as Fletcher met Rory Macleod’s cross with a sweetly timed left-footed volley, but it cannoned off the angle of post and bar as Saints held on to secure three priceless points.