Even if he does not score another goal until the end of May, Zlatan Ibrahimovic could claim to have had one of the great debut seasons in the history of Manchester United.

The goal that took Jose Mourinho’s side into the quarter-finals of the FA Cup was his 24th of the season and delivered with an assassin’s precision. He did not even start this game but with Blackburn producing fierce resistance for a side teetering on the edge of relegation to the third tier of English football, he and Paul Pogba were introduced together.

Between them they settled the tie. A long ball from Pogba hung for an age in the soaking air, Ibrahimovic took it down beautifully and clipped it into the net beneath the 7,200 Manchester United supporters who crammed the Darwen End.

Ibrahimovic came off the bench to score the winnner (Getty) (Getty Images)

It was so nearly a replay and there were times when you thought United might not get even that. On Saturday, Blackburn supporters would have relished Burnley’s humiliation at the hands of Lincoln, one of the great upsets in the annals of the FA Cup.

Not long into the afternoon it appeared Ewood might be enjoying the perfect FA Cup weekend. They had begun aggressively and, when Blackburn took the lead, it was not against the run of play.

It was a goal made by a Swansea player and scored by a former one. Swansea had not allowed their on-loan striker, Marvin Emnes, to play in the third round of the FA Cup but since the Dutch forward has lasted longer in the competition than they have, his participation was no longer an issue.

Graham put Blackburn in front in the first-half (Getty) (Getty Images)

He had already stung Sergio Romero’s gloves with one shot from outside the area and the Argentine keeper was fortunate the rebound fell into space rather than to a Blackburn boot. Four minutes from the end, Romero’s failure to hold a shot almost produced a Blackburn equaliser but Anthony Stokes was obviously offside when he shot the ricochet home.

The next time Emnes had the ball at his feet, Manchester United paid the price. Emnes turned Marcos Rojo easily on the edge of the area and his pass to Danny Graham split Chris Smalling and Ashley Young.

When Graham was at Sunderland, he was famous for not scoring goals. The £5m Sunderland paid Swansea for the centre-forward’s services brought them a grand total of one goal. The fact Graham was a Newcastle supporter who had vowed never to set foot in the city only endeared him to Wearside less. However, on the grand stage, Graham demonstrated he knew exactly how to finish. The shot left Romero helpless.

Graham celebrates his opening goal (Getty) (Getty Images)

Manchester United’s reply was even better. Mourinho had stuffed his bench full of his prize assets – Bailly, Ibrahimovic Pogba and Mata – while for the first hour at least his attack on the pitch was entrusted to the young talents of Lingard, Rashford and Martial. Marcus Rashford took the equaliser coolly enough but it was created by the brilliance of Henrikh Mkhitaryan.

The move began with Romero rolling the ball to the Armenian deep inside his own area. Mkhitaryan had to stretch for the ball, there was a Blackburn player closing in, he might have pulled out. Mkhitaryan kept his nerve, began his run and then on the halfway line launched a gorgeous pass towards Rashford. He drew the keeper, took the ball past Jason Steele and passed it into the net.

Rashford is not quite replicating the dreamlike start to his Manchester United career he enjoyed under Louis van Gaal last season – he has not scored in the Premier League since September - but this was his third goal of this FA Cup campaign.

Rashford hit back for Manchester United (Getty) (Getty Images)

This had the feel of the old games between Blackburn and Manchester United when they would meet, if not as equals, then as two clubs driven by similar ambitions. For a Lancashire derby, the weather was prefect, swirling February rain lit up by Ewood’s floodlights.