Sunderland threw away a two-goal lead in the final ten minutes as they were held to a draw at Fleetwood Town which saw them knocked off the top of the table by Wigan on goal difference.
The Black Cats had gone in front at Highbury Stadium after 20 minutes through Ross Stewart's fifth goal of the season.
Sunderland had chances to add to their lead, with Embleton and Aiden McGeady off-target in the first half, and McGeady bringing a good save out of Alex Cairns in the second.
Fleetwood created a great chance to equalise midway through the second period, but Carl Winchester got back to make a brilliant block to deny Morton.
Sunderland doubled their lead 15 minutes from the end when McGeady converted from the spot after Luke O'Nien had been fouled by Harrison Biggins.
But Fleetwood pulled a goal back in the final ten minutes through the dangerous Morton, meaning the Black Cats could not relax in the closing stages.
And they buckled in the sixth minute of injury time as Bailey Wright was penalised for a foul on Morton, and Ged Garner tucked away the penalty.
0-1 Stewart 19mins
Embleton's free-kick from the right found Stewart at the near post where he had got in front of his marker, and he glanced his header past Cairns from six yards out
0-2 McGeady (pen) 76mins
Cairns got a hand to McGeady's spot-kick but could not keep it out, after Biggins had given away the penalty for tugging back O'Nien at a corner
1-2 Morton 81mins
Collected Lane's pass on the edge of the box, burst into the area and slotted low past Hoffmann
2-2 G Garner (pen) 90+6mins
Converted from the penalty spot after Wright was adjudged to have pulled Morton's shirt inside the area
Lee Johnson made one change to the side that started last weekend's win against Accrington Stanley, and that alteration was forced upon him.
Tom Flanagan picked up his fifth booking of the season against Accrington, meaning he missed Sunderland's trip to Fleetwood Town through suspension, and his place was taken by Bailey Wright.
Wright's promotion to the starting line-up left a vacancy on the bench which was filled by deadline day signing Leon Dajaku, with the on-loan Union Berlin winger included in the matchday squad for the first time.
Thorben Hoffman, who made his debut against Accrington, kept his place in goal ahead of Lee Burge, while Johnson opted to stick with the midfield pairing of Luke O'Nien and Dan Neil which meant Corry Evans was again on the bench.
Fleetwood boss Simon Grayson, who had a short spell in charge of Sunderland in 2017, also made one change to his starting XI, in his case to the side that won 4-2 at Rotherham last time out.
Max Clark came into defence in place of the injured Darnell Johnson.
Fleetwood Town: Cairns, Hill, Clarke, Clark (J Garner 46), C Johnson, Biggins (Lane 76), Rossiter, Camps, Andrew, G Garner, Morton. Subs not used: Crellin, Edmondson, Matete, Baggley, Conn-Clarke
Booked: J Garner, G Garner
Sunderland:Hoffmann, Winchester, Wright, Doyle, Cirkin, O'Nien, Neil (Evans 67), Gooch, Embleton (Broadhead 72), McGeady (Alves 90), Stewart. Subs not used: Burge, Huggins, Dajaku, Pritchard
Referee: Neil Hair (Huntingdonshire)
The shoddy defending that ended in Morton's goal, which gave Fleetwood hope
Hoffmann made a string of impressive saves, and couldn't be faulted for either Fleetwood goal
This was a huge disappointment for Sunderland as they let two points slip through their fingers.
The game was as good as won with ten minutes to go, but poor defending gave Fleetwood a route back into the game and then they fell to the sucker punch of a contentious penalty in injury-time.
They should have been celebrating their sixth win in seven league outings, but instead they must reflect on their first draw of the season which saw them deposed by Wigan at the top of the table.