Manchester United's Zlatan Ibrahimovic came off the bench to score the winner as they recovered from an early deficit to beat Championship strugglers Blackburn Rovers 2-1 away in the FA Cup fifth round on Sunday. The Swedish hitman entered the fray just part the hour mark at a murky Ewood Park and produced a typically silky finish in the 75th minute to spare holders United an unwanted replay. It was his first goal in the FA Cup and 24th in all competitions and sent 12-times winners United into the quarter-finals where they will play at Premier League leaders Chelsea. United's passage was far from smooth, though, against the former Premier League champions who are now struggling to retain their second-tier status. Until United manager Jose Mourinho sent on Ibrahimovic and world record signing Paul Pogba in the 62nd minute the visitors were finding Blackburn a tough nut to crack. Danny Graham had put the hosts ahead before United forward Marcus Rashford equalised just before the half-hour mark. Then, in a moment of supreme quality, Pogba's flighted pass found Ibrahimovic running in behind the Rovers rearguard and the veteran striker took his time before guiding a shot past keeper Jason Steele. "Did they give us a good game? More than good, they gave us a hard game and congratulations to them," Mourinho, who won the Cup 10 years ago with Chelsea, said. "Their approach was brave, strong. They had real competitors and if we didn't have the right attitude from everybody we would be in real trouble." Mourinho even graciously applauded as Rovers took the lead with a goal of real quality in the 17th minute. The lively Marvin Emnes did superbly to work some space before slipping an astute pass to Graham who finished superbly into the far corner with an angled shot. "We conceded a brilliant goal," Mourinho said, although it was matched by the quality of United's equaliser. There looked little danger when Henrikh Mkhitaryan received the ball inside his own half but he dissected the Rovers defence with a pass played with the outside of his left foot and Rashford rounded Steele before sliding home. United dominated thereafter but still needed some inspired intervention from their substitutes to seal victory. Blackburn never gave up the cause, though, and thought they had scrambled a late equaliser when Anthony Stokes poked the ball home but a linesman's flag cut short the celebrations. United's success means the fixtures are coming thick and fast as they prepare to visit St Etienne in the Europa League last 32 on Wednesday, protecting a 3-0 first leg lead, then face Southampton in the League Cup final at Wembley next Sunday. "Southampton is sleeping, is eating and resting and working for the League Cup final and we have had to play three tough games," Mourinho said. "It is so much more difficult for us, but for good reasons," added Mourinho, who can now also look forward to visiting his old club Chelsea in the FA Cup sixth round.