From the moment Bristol City’s official Twitter account pointed out pre-match that this was the first time in their history they would play under the watchful eye of VAR, you always felt it would come back to haunt them. Not that they can have any complaints, mind: either about the moment which swung this cup tie in Sheffield United’s favour, or the final outcome itself. The Championship side battled gamely at Bramall Lane but were ultimately beaten by a Sheffield United side who could yet look back on this FA Cup run as significant. For the second consecutive season, the Blades are into the quarter-finals, but this latest run has been a catalyst for much greater things elsewhere, too. Having failed to win any of their first 18 games of the season, victory against League One side Bristol Rovers in the third round was the start of a run of six wins in nine games in all competitions, the latest here against the side from the other half of Bristol. They will need another run akin to this in the Premier League to survive against the odds, but for now, their season remains alive. “I thought we were in control against stubborn opposition,” Chris Wilder said. “The key, as we have done already, is to use this momentum going into the next few games.” Billy Sharp went to Sheffield United’s last FA Cup semi-final as a fan in 2014, but it was his penalty here that moved them to within one win of their own day out at Wembley. Now 35, his mid-season renaissance – this was his fourth goal in eight games – has mirrored his own team’s upturn in form. “Billy’s scored goals all throughout his career,” Wilder said. “We had to be right with our attitude point of view and positive with our play, which I believe we were.” Sharp’s 66th-minute strike was the difference here, but United had dominated for large periods leading up to the winner. However, the game’s defining moment came when VAR interfered after David McGoldrick’s goal-bound effort struck Alfie Mawson. On review, Mawson was adjudged to have handled, awarding the home side a penalty and earning himself a straight red. Sharp converted with minimal fuss for his fifth of the season, and with a man advantage, United had enough nous to steer out the final 20 minutes with very little drama. Bristol City’s best chances came either side of half-time, first when Tomas Kalas fired straight at Aaron Ramsdale, before Nahki Wells had an opportunity to pass for a possible goal, but instead chose to shoot. And they were ultimately made to rue the moment when Mawson saw red and Sharp punished the Championship side. “It was a really disappointing way to lose the game,” Dean Holden, the Bristol City head coach, said. “In fairness to the referee, he’s playing by the rules but if this was played at Ashton Gate, it wouldn’t have been given because we don’t have VAR at Championship stadiums.”