United's win, their fourth without conceding a goal since their 6-1 home loss to City last month, was overshadowed by Ferguson's silver anniversary occasion and was far from glittering, with the winner coming from former United defender Wes Brown, who put through his own net just before half-time.
But City stayed clear at the top when they won a five-goal thriller at Loftus Road, where Yaya Toure headed home the winner 16 minutes from time.
It was an emotional day at Old Trafford but the game will not live as long in the memory as the other events on the day, with United's chief executive, David Gill, announcing the North Stand had been renamed the "Sir Alex Ferguson Stand" and that a statue of the 69-year-old Scot was being commissioned to mark his achievements for the club since he took over on November 6 1986.
Ferguson admitted to Sky Sports afterwards: "I thought we were anxious but in the second half we improved, although the last 15 minutes was torture.
"I don't know whether it was down to the way Sunderland played, or the occasion; these emotional occasions, which it was for me today, sometimes get through to them."
Despite losing, Blackburn, who have now lost five of their six home league games, played quite well but could find no way past Chelsea goalkeeper Petr Cech, who ended the match with a broken nose after colliding with Rovers' Yakubu Aiyegbeni and Ashley Cole, which caused a seven-minute holdup.
Chelsea manager Andre Villas-Boas, pleased his side won after two successive defeats, added: "Petr broke his nose. He's very injury-prone in football accidents, all sorts of things have happened to him but he hung on bravely tod
