Charlton were unable to overcome an early Middlesbrough goal as they lost 1-0 to their relegation rivals at The Valley.
Paddy McNair gave the visitors a 17th minute lead who held on to move ahead of the Addicks in the table with results elsewhere leaving Charlton in the relegation zone.
Darren Pratley returned to the starting lineup after five games on the sidelines as Lee Bowyer made three changes with Jonny Williams and Ben Purrington joining him as the Addicks started in a 4-diamond-2 formation.
Both sides battled for superiority in a tense opening quarter of an hour and the Addicks got in behind the Middlesbrough defence in the 14th minute when Josh Cullen played in Andre Green whose shot was blocked behind by Ryan Shotton.
Green turned creator just minutes later with a deep cross from the right which was met by a diving Lyle Taylor who couldn’t quite direct his first-time effort on target.
Middlesbrough took the lead a minute later when they robbed the Addicks in their own half and McNair clinically slotted the ball home.
The Addicks switched to a 4-4-2 as the half wore on with Green moving from the right wing to partner Taylor up front.
Charlton had the better of the chances as the half wore on, Pratley skied after getting into the box and Green then headed wide from a Matthews cross. Green also saw a driven effort bounce off the visitors’ goalkeeper Dejan Stojanovic on the 40 minute mark.
Macauley Bonne replaced George Lapslie at half-time as he partnered Taylor with Green moving back to the right wing with the Addicks remaining in a 4-4-2 formation.
The Addicks had a loud penalty appeal turned down in the 52nd minute when Taylor went down under the attention of Shotton, already on a yellow card, but referee Stephen Martin adjudged the striker to have dived and booked him for simulation.
That spurred on the Addicks players and fans and a spell of pressure followed with Charlton creating chance after chance.
A Williams cross was well met by Deji Oshilaja but his header was straight at Stojanovic. Bonne then got in behind and crossed to Pratley who couldn’t quite control his effort on target.
At the other end Adam Matthews covered well to deny Lewis Wing a counter attack goal.
In the 70th minute a clever Taylor cross from the left made it’s way through to Bonne for maybe the Addicks best chance of the game but his toed effort was straight at Stojanovic.
Marcus Tavernier could have doubled the lead cutting in from the right but his left-footed effort was bravely blocked by Pearce. Dillon Phillips pulled out an outstanding save to deny Wing with six minutes remaining as the Addicks prepared for a final push.
Bonne headed a stoppage time cross from Oshilaja wide of goal with the Addicks last chance of the game.
Charlton: Phillips; Matthews, Oshilaja, Pearce (C), Purrington (Hemed 83); Cullen, Pratley, Lapslie (Bonne 46); Green, Taylor, Williams (Doughty 66)
Subs (not used): Amos, Davis, Smith, McGeady
Booked: Purrington 45 (foul on Howson), Taylor 52 (simulation), Matthews 63 (foul on Clayton)
Middlesbrough: Stojanovic, Shotton, Tavernier (Spence 87), Clayton, Gestede, Howson (C), McNair (Saville 81), Moukoudi, Johnson, Wing, Coulson
Subs (not used): Pears, Assombalonga, Fletcher, Morrison, Nmecha
Goal: McNair 17
Booked: Shotton 11 (foul on Taylor)
Referee: S Martin
Attendance: 18,080 (1,750 from Middlesbrough)