Les Reed has left Charlton by mutual consent and Alan Pardew has been appointed as his replacement at The Valley.
Pardew, who was sacked by West Ham earlier this month, has signed a three-and-a-half-year deal and becomes the club's third manager this season.
Reed was promoted from the role of assistant boss in mid-November when Iain Dowie lost his job with the Addicks' bottom of the Barclays Premiership but has failed to turn their fortunes around during his month at the helm.
Dowie was appointed as Alan Curbishley's replacement in the summer, with Reed given the job upon the former Crystal Palace boss' departure.
But the former Football Association technical director managed just one win from his eight games in charge and presided over last week's Carling Cup quarter-final defeat at home to Coca-Cola League Two Wycombe.
Despite assurances before that game the club had no intention of changing managers before the end of the current campaign, yesterday's 2-0 defeat at Boro proved the final straw.
Pardew's first match in charge will be Wednesday's London derby with Fulham.