Sheffield United sent Aston Villa crashing out of the FA Cup in the third round for the fourth successive year. Andy Liddell struck twice in the last 10 minutes as a close-fought tie looked to be heading for a replay. Gareth Barry’s 20-yard drive gave Villa the lead a minute after the break, but Danny Cullip levelled after 57 minutes. Liddell put United ahead as he managed to fire a close-range finish past Thomas Sorensen, who then allowed his shot to slip in two minutes later. The Championship underdogs, semi-finalists and quarter-finalists in the last two years, dominated the opening half. Villa goalkeeper Sorensen was outstanding in the first 45 minutes with a string of fine saves, saving well from Andy Gray and turning over a close-range header from Jagielka after 32 minutes. He was in action again seconds later when Michael Tonge played in Wayne Quinn, and Sorensen blocked another good opportunity from the edge of the area. Villa’s only serious response had been a volley from Carlton Cole that was easily held by Blades’ keeper Paddy Kenny - but they struck against the run of play a minute after the interval to take the lead. Hendrie prodded a through ball to Barry, who escaped the attentions of the home defence to lift a powerful finish over Kenny from the edge of the area. But the Blades were not thrown out of their stride, and deservedly equalised after 55 minutes. Jon Harley’s cross from a short corner saw Cullip steal away from marker Olof Mellberg to stab past Sorensen from inside the six-yard box. Tonge had been a danger for the Blades and he curled a shot narrowly off target as Villa came under pressure with 15 minutes left. And the tie was settled as the Blades struck twice in two minutes late on to stun Villa. Liddell burst away from the Villa defence to beat Sorensen from eight yards after 81 minutes - before goalkeeper Sorensen was guilty of another calamitous error two minutes later. Sorensen looked to have Liddell’s powerful angled drive covered, but let it slip through his fingers to send Bramall Lane wild with delight.