A DRAMATIC leveller in the 11th minute of stoppage-time from Kalvin Phillips earned Leeds United a dramatic point in a pulsating encounter at the Riverside Stadium.
A long delay with around ten minutes to go with medical staff converging close to the away dug-out resulted in 12 minutes of added-on time with Leeds rescuing a point when Phillips headed home following Gianni Alioski's corner.
It was subsequently revealed that Jack Clarke, who went off at the break after feeling unwell, was treated by medical staff and after recieving attention, he was taken to hospital to be checked over, accompanied by Rob Price, Leeds head of medicine and performance.
Boro had taken the lead straight after the restart when Lewis Wing - who later went off due to injury - fired home confidently, an advantage that the hosts merited.
But Phillips had the final say for Leeds.
Leeds made three changes with Phillips and Jack Clarke coming into the side alongside Boro old boy Patrick Bamford, handed his first league start for the Whites at a place he knows well.
Jordan Hugill lined up from the off for Boro after shrugging off the niggle which saw him forced off in the embarassing FA Cup exit at Newport.
It was a first half in which both sides were afforded encouragement in an entertaining spectacle played out in front of a big crowd.
Boro went the closest after producing a strong spell at the mid-way point of the half after a slow opening.
Keeper Kiko Casilla did well to made a fine one-handed save to deny George Saville and from the resulting corner, Aden Flint headed over with the goal at his mercy.
Flint then beat the ground in frustration after failing to get a clean header following a pinpoint cross from Shotton, who was soon left to bemoan his fortune after not getting a telling connection in front of goal after ghosting in unmarked from George Friend's low crss from the left.
A strike from Lewis Wing also whistled just wide for the hosts.
Leeds, who started brightly and produced some nice passing combinations, contrived an early chance when Mateusz Klich hooked wide when well placed while Bamford was wasteful later on in the half after being played in by ex-Boro loanee Jack Harrison, tentatively firing off target.
The impression at the interval was that one moment of class or a mistake may define this meeting.
In the event, the former arrived with Leeds undressed down their right and Boro forging the breakthrough.
Mikel won the ball in midfield and supplied Saville, whose instinctive pass dissected Leed,s with the supporting Friend firing over a sweet low cross which found Wing, who kept his composure in front of goal to steer the ball past Casilla.
Leeds' riposte initially lacked conviction, but they eventually forged a strong response and went desperately close to levelling in a powerful spell.
First, Darren Randolph was forced into action twice to make key blocks to deny Kemar Roofe before the post came to Boro's rescue.
Harrison's cross was met by Pontus Jansson, whose fine downward header struck the post, with Bamford putting the follow-up wide.
At the other end, a stretching Friend steered the ball wide from Besic's centre before another replacement in Assombalonga went close at the near post.
Most of the pressure was at the other end before a substantial break away arrived amid worrying scenes near to Leeds dug-out, with a long delay ensuing as medics administered treatment.
Play eventually resumed and deep, deep into stoppage time, Leeds rescued a point courtesy of Phillips.
Middlesbrough: Randolph; Ayala, Flint, Fry; Shotton, Mikel, Saville (Clayton 78), Howson, Friend; Wing (Besic 64), Hugill (Assombalonga 77). Substitutes unused: Dimi, Fletcher, Downing, van La Parra.
Leeds United: Casilla, Ayling (Shackleton 80), Jansson, Cooper; Harrison, Phillips, Klich (Roberts 58), Alioski; Clarke (Hernandez 45), Roofe, Bamford. Substitutes unused: Peacock-Farrell, Brown, Davis, Halme.
Referee: D England (South Yorkshire).
Attendance: 30,881 (4,489 Leeds United supporters).