The Saints are now one win away from a spot in the Scottish Cup final and - with a semi against either Dundee United or Motherwell on April 16 - they are a realistic chance.

Invincibile, who joined the Saints in February after being released by Kilmarnock in January, started and played a full game in the quarter-final victory.

The Australian had a chance to open the scoring on 16 minutes when his low shot from the edge of the box was brilliantly pushed behind by Brechin keeper Craig Nelson.

On 27 minutes, Invincibile had another chance when he volleyed Chris Millar's cross off target at the back post.

Third tier Brechin put the Saints under some pressure, before Collin Samuel got the winner on 37 minutes with a rifled shot from a tight angle.

Invincibile could have put the tie to bed on 71 minutes when he drove high, but 1-0 was enough for the Perth club who will aim to reach their first ever Scottish Cup final.

Elsewhere overnight, in England's League Two, Alex Cisak played a full game and kept a clean sheet as Accrington Stanley drew 0-0 at Crewe.

Cisak made a fine save in a one-on-one situation against Crewe's Danny Shelley in the first-half to keep it goalless.

Meanwhile, Jamie Young put in a full shift and also kept a clean sheet following a spectacular reaction save to deny a first-half effort as Aldershot defeated Barnet 1-0.