United’s captain was in the right place at the right time twice in the second half with a close-range tap-in and then a header.
It was the least Chris Wilder’s team deserved after a performance full of swagger that gave the Blades their first win on this ground since November 1986, when their captain was only 10 months old.
It would have been a much greater margin of victory but for Rovers goalkeeper David Raya, who distinguished himself, but ultimately there was to be no reward, as United notched a fourth win in five away games this season. The result ends Blackburn’s 25-match unbeaten home run – a post-war club record – but they were outclassed by a more accomplished team.
The early exchanges were dominated by probing United passing, ultimately unlocking a chance for Mark Duffy in the 25th minute, who swivelled and let fly with a rasping low drive that Raya did well to parry.
Sharp’s looping header caused panic in the Blackburn box, and while Harrison Reed and Bradley Dack saw shots blocked, these were only fleeting sights of goal.
Raya repelled a powerful downward header from former Rover Jack O’Connell and before the half ended, the Spaniard superbly tipped over a curling David McGoldrick effort.
United got the goal their play deserved in the 66th minute through a typically flowing move that saw Fleck play in McGoldrick on the left. His searching low cross was met by the sliding Sharp, whose initial effort was partially blocked but he recovered to tap into the empty net.
And Sharp put the gloss on a dominant performance 11 minutes from the end, when he was on the end of an inch-perfect Enda Stevens cross to head in his eighth of the season from close range. Paul Coutts, who broke his leg last season, made a welcome appearance off the bench.