Match ends, Middlesbrough 1, Leeds United 1.
Leeds United moved to the top of the Championship as Kalvin Phillips equalised in the 11th minute of injury time against Middlesbrough.
Play was held up late in the second half while paramedics tended to Leeds teenager Jack Clarke, who reported feeling unwell after coming off at half-time.
The 18-year-old was carried off on a stretcher receiving oxygen and taken to hospital as a precaution, but Leeds boss Marcelo Bielsa confirmed he was feeling better in the dressing room.
The delay resulted in 12 minutes being added on and Phillips headed past Darren Randolph in the 101st minute to take his side a point clear of Norwich, who slip to second.
Middlesbrough seemed certain to bounce back with a victory following their shock FA Cup defeat at Newport in midweek after Lewis Wing had scored from 12 yards early in the second half.
Leeds went close to equalising at the Riverside when Pontus Jansson's header hit the post before Phillips' dramatic leveller.
Norwich will retake top spot on Sunday if they avoid losing to bottom side Ipswich.
Despite the loss at League Two Newport in their fourth-round replay on Tuesday, Boro are in good form in the Championship. They are unbeaten in six matches and have taken four points from fellow promotion contenders West Bromwich Albion, and now Leeds, in successive weeks.
The two sides drew 0-0 at Elland Road in August, and the game looked to be heading the same way after a lacklustre first half.
But 23-year-old Wing showed excellent composure just two minutes after the break to place the ball past Kiko Casilla while under pressure in the box.
Leeds dominated possession over the 90 minutes, but failed to create any clear-cut chances until midway through the second half. First Kemar Roofe was denied twice by Boro goalkeeper Randolph before Jansson glanced his header against the upright and former Boro striker Patrick Bamford skewed the rebound off target.
However, Leeds were not made to pay for those missed opportunities as Phillips netted his first goal of the season from Liam Cooper's flick.
Middlesbrough manager Tony Pulis told BBC Tees:
"In the first half we were the better team and our midfield players were fabulous. When we were attacking, we were having five or six players in the box and around that area, which was fantastic.
"We tired a bit in the second half, Leeds came into it as the game went on, and we certainly didn't need to concede a goal from a set-play - something that's really disappointed me."
Leeds head coach Marcelo Bielsa told BBC Radio Leeds:
"We could have won the game. We had 15 minutes in the first half where we were not at ease, but apart from that segment we dominated the game, we created chances, we deserved to score the goal and probably deserved to score other goals."
Line-ups
Middlesbrough
Formation 3-4-2-1
- 23Randolph
- 4Ayala
- 24Flint
- 20Fry
- 5Shotton
- 2Mikel
- 22SavilleBooked at 59minsSubstituted forClaytonat 78'minutes
- 3Friend
- 26WingSubstituted forBesicat 64'minutes
- 16HowsonBooked at 90mins
- 11HugillSubstituted forAssombalongaat 77'minutes
Substitutes
- 1Konstantopoulos
- 8Clayton
- 9Assombalonga
- 18Fletcher
- 19Downing
- 29van La Parra
- 37Besic
Leeds
Formation 4-1-4-1
- 33Casilla
- 2AylingSubstituted forShackletonat 80'minutes
- 18JanssonBooked at 90mins
- 6Cooper
- 10Alioski
- 23Phillips
- 22Harrison
- 7Roofe
- 43KlichSubstituted forRobertsat 58'minutes
- 47ClarkeSubstituted forHernándezat 45'minutes
- 9Bamford
Substitutes
- 1Peacock-Farrell
- 11Roberts
- 19Hernández
- 37Brown
- 40Davis
- 46Shackleton
- 52Halme
- Referee:
- Darren England
- Attendance:
- 30,881
Match Stats
- Possession
- Home31%
- Away69%
- Shots
- Home9
- Away17
- Shots on Target
- Home3
- Away4
- Corners
- Home2
- Away9
- Fouls
- Home11
- Away8
Live Text
Post update
Booking
Pontus Jansson (Leeds United) is shown the yellow card.
Full Time
Second Half ends, Middlesbrough 1, Leeds United 1.
Goal!
Goal! Middlesbrough 1, Leeds United 1. Kalvin Phillips (Leeds United) header from very close range to the centre of the goal. Assisted by Liam Cooper with a headed pass following a corner.
Post update
Corner, Leeds United. Conceded by Ryan Shotton.
Booking
Jonny Howson (Middlesbrough) is shown the yellow card for hand ball.
Post update
Hand ball by Jonny Howson (Middlesbrough).
Post update
Corner, Leeds United. Conceded by Ryan Shotton.
Post update
Attempt blocked. Jack Harrison (Leeds United) left footed shot from the left side of the box is blocked. Assisted by Kalvin Phillips.
Post update
Corner, Middlesbrough. Conceded by Liam Cooper.
Post update
Foul by Kalvin Phillips (Leeds United).
Post update
John Obi Mikel (Middlesbrough) wins a free kick in the defensive half.
Post update
Attempt missed. Tyler Roberts (Leeds United) right footed shot from the right side of the box is too high. Assisted by Pablo Hernández.
Post update
Jack Harrison (Leeds United) wins a free kick on the left wing.
Post update
Foul by Britt Assombalonga (Middlesbrough).
Post update
Delay over. They are ready to continue.
Post update
Delay in match (Leeds United).
Post update
Corner, Leeds United. Conceded by Ryan Shotton.
Substitution
Substitution, Leeds United. Jamie Shackleton replaces Luke Ayling.
Post update
Attempt missed. Britt Assombalonga (Middlesbrough) right footed shot from the right side of the box is close, but misses to the right. Assisted by Muhamed Besic.