The Black Cats had looked set to claim their seventh win in a row against Newcastle United as they led their rivals 1-0 at St James’ Park after a first-half strike from Jermain Defoe.
But, with 83 minutes on the clock, the Serbian star kept their survival hopes alive as he nodded a back-post header beyond Vito Mannone in new boss Rafael Benitez’s first derby.
And such was Mitrovic’s keenness to help his side against their fierce rivals he had to be restrained and kept off the field after being knocked out in added time.
In another eventful and fascinating clash between the two rivals, Defoe was the first to fire a shot on goal but hit a Fabio Borini knockdown well over the bar and into the Gallowgate End, but his chance brought Newcastle to life.
A Moussa Sissoko run down the left had the Sunderland defence on the back foot, while Mitrovic fired a first-time volley over the crossbar.
Both sides were casual with possession and a sloppy tackle on Borini from Jack Colback, in at left-back, saw him earn the game’s first booking.
Defoe struck the side-netting and Andros Townsend forced Vito Mannone into a save as the end-to-end clash continued.
Newcastle’s frontline showed signs of clicking as the crowd roared on the players and Shelvey saw his low free-kick slip wide of the post after a foul on the intelligent Ayoze Perez.
Wahib Khazri has impressed for the Black Cats in recent weeks but was unable to get into the match too much and a wayward long-range free-kick was his first offering to the match.
Meanwhile, Lamine Kone provided a moment of light-relief for both sets of fans – and an amused Sam Allardyce – when the big centre-back powered into a good position on the right flank but proceeded to twist himself into knots as he attempted to shield the ball, running it aimlessly out of play.
Just when it looked the first half would end goalless, Sunderland left their rivals rattled as Defoe slammed and effort beyond Elliot after he had made an excellent stop to deny Borini’s thunderous strike.
Moments after the restart Perez saw his goal-bound effort cleared off the line by Yann M’Vila, while Shelvey was cautioned for a clumsy challenge on Jan Kirchhoff, who has adapted well after a shocking start to Premier League life against Tottenham.
Elliot had to be at his best to deny a Patrick van Aanholt thunderbolt inside the area as Sunderland threatened to grab a second goal on the counter.
And as Benitez looked to turn the match around he took off Colback and shuffled France international Sissoko to full-back and brought on Siem de Jong, who brightened proceedings, but still the Magpies couldn’t get any clear cut chances on Mannone’s goal.
Perez shanked a volley into the stand after making space for himself and Shelvey, again, failed to connect properly with a strike from outside the box as Newcastle pushed forward.
But just when it looked like the hosts were running out of ideas again Mitrovic leapt highest at the back post to nod home a Georginio Wijnaldum cross. And the Serbian celebrated wildy, ripping his shirt off and enjoying the moment with a fan who had run onto the pitch.
His afternoon came to a premature end when he was knocked out in the dying stages and Benitez stopped him from returning to the field, but his team-mates, despite one late scare, managed to hold onto a precious point.