Callum Davidson's Premiership outfit threatened early on with Glenn Middleton cutting into the box before a goal-bound effort was tipped round the post by Derek Gaston.

Arbroath took the lead on the half-hour mark with a dangerous corner from the right by Nicky Low giving St Johnstone trouble and Joel Nouble tapped the ball home from a few yards out.

The cup holders pressed hard to respond immediately with Stevie May heading an effort wide and a half-volley by Callum Hendry forcing a save from Gaston.

A stunning volley from 20 yards by Colin Hamilton almost doubled Arbroath's advantage, but former Aston Villa goalkeeper Elliott Parish was alert to the danger.

St Johnstone levelled just before the hour mark after being awarded a penalty when Reece Devine was brought down inside the box.

Kerr stepped up and attempted to smash the spot-kick down the middle but an outstretched save by Gaston denied the captain, although Middleton was there to pick up the rebound and tap home from close range.

Both sides searched for a winner before the end of normal time with Middleton almost setting Gayfield Park alight with an effort from 18 yards which smashed off the crossbar before Gaston gathered the ball.

Nouble then found Michael McKenna for the hosts with a lovely ball from the right which the midfielder just headed over.

Arbroath took the lead for the second time just a couple of minutes into extra-time with a Linn corner initially cleared by the home defence and landing into the path of Thomas O'Brien, who sweetly struck a volley into the roof of the net past the stranded Parish.

St Johnstone bounced back again after 105 minutes with a Liam Craig delivery from the left finding the unmarked Jamie McCart, who guided home a fine header past Gaston before the match went to penalties.