Albion Rovers have knocked Motherwell out of the Scottish Cup with a 1-0 home win in the fourth round.
Gary Phillips's left-footed shot in the final minute of normal time saw the League Two side get the better of the Premiership outfit at Cliftonhill in Coatbridge.
Queen of the South almost emulated Rovers as they twice came from behind to earn a 2-2 draw with St Mirren at Palmerston Park in Dumfries.
Conor Newton put the visitors in front after nine minutes, but Iain Russell restored parity before the break.
The Scottish Premiership club surged ahead just six minutes after the interval when Steven Thompson scored his sixth goal of the season.
However, Jim McIntyre's side kept alive their Scottish Cup hopes by earning a replay as Michael Paton made it 2-2 on 72 minutes.
Premiership duo St Johnstone and Hibernian both progressed to the fifth round with victories over Livingston and Ross County respectively.
The start of the second half of the fourth-round encounter between Inverness Caledonian Thistle and Greenock Morton were held up by more than 30 minutes because of a power failure, but that did not deter the hosts from winning 4-0.
Inverness went ahead on the stroke of half time when Nick Ross found the target from the penalty spot.
Billy McKay headed his side into a 2-0 lead in the 71st minute and doubled his tally in the final minute of normal time.
Then Morton's Scott Taggart was shown a straight red for his challenge on Torbjorn Agdestein deep into injury time inside the box and Aaron Doran converted the resulting penalty.
Results in full: Burton 1-0 Motherwell, Inverness CT 4-0 Greenock Morton, Queen of the South 2-2 St Mirren, Ross County 0-1 Hibernian, St Johnstone 2-0 Livingston