Sheffield United skipper David Holdsworth scored his third vital goal in four games to help set up a money-spinning FA Cup fifth round clash at Double-winners Arsenal.

Holdsworth's 52nd-minute scrambled effort sparked a rampant second-half performance as United celebrated their biggest win since boss Steve Bruce took over last summer.

After four months out with a knee injury, Holdsworth returned to grab a vital 89th-minute equaliser in a 2-2 draw at Swindon nearly three weeks ago.

Then, in Saturday's third round replay at Notts County it was Holdsworth's goal five minutes from time which gave the Blades new heart after they had trailed 3-1, eventually winning 4-3 in extra-time.

The central defender is now beginning to outshine Bolton striker and brother Dean up front, with his goal knocking the stuffing out of Third Division leaders Cardiff.

The last 16 tie at Highbury was sealed six minutes later when 18-year-old sub Lee Morris, on at half-time for Michael Twiss, rammed home his first goal for the club in his 15th appearance - all from the bench.

Marcelo and Graham Stuart then both went close before the former Chelsea and Everton midfielder drove home the fourth off the legs of keeper Jon Hallworth, who had earlier proved the hero.

The Blades could have been four goals clear by the time Kevin Nugent headed a 19th-minute equaliser, but for the agility of Hallworth.

Holdsworth and Paul Devlin were both denied by superb saves by the former Oldham number one, before the latter made no mistake for the opener in the 13th minute, sidefooting home a Vas Borbokis right-wing cross from six yards.

Hallworth's best of the half followed within three minutes as Borbokis looked certain to score from point-blank range with a near-post flick, only for Hallworth to brilliantly block.

It spurred the visitors, who capitalised within three minutes and it was all credit to leading scorer John Williams.

With the ball running out of play for a goal-kick, Williams chased a lost cause and managed to hook it over his head for Kevin Nugent to nod home his 12th of the season.

The forward clattered keeper Alan Kelly in the process, who required lengthy treatment, but Stockton referee Jeff Winter let the goal stand.

After a stale spell, Cardiff should have gone into the break a goal up, but Craig Middleton shaved the left-hand post with a free header in the 42nd minute before a stunning chance moments later.

Middleton's ball was knocked across the face of goal by Williams and just when former Blade Jeff Eckhardt looked as if was going to stab home from a yard, Kelly somehow flicked the ball off his toes.

They paid the price as United grabbed the game by the scruff of the neck following the interval, with the only blemish on the night the moment when assistant-manager John Deehan was ordered from the touchline in the 45th minute.

Deehan is still awaiting to appear in court after being arrested by a policewoman for foul and abusive language during the game at QPR in late November.

On this occasion the incident was not as serious, Deehan having strong words with a linesman, resulting in him being sent to the stands by referee Winter.

Teams:

Sheff Utd: Kelly, Borbokis (Ford 60), Quinn, Derry, Sandford, Holdsworth, Woodhouse (Henry 78), Twiss (Morris 46), Marcelo, Devlin, Stuart.

Subs Not Used: Tracey, Jacobsen.

Goals: Devlin 13, Holdsworth 52, Morris 58, Stuart 68.

Cardiff: Hallworth, Delaney, Ford, Mitchell, Eckhardt, Carpenter, Fowler, O'Sullivan (Legg 60), Williams (Bowen 60), Nugent, Middleton (Hill 65).

Subs Not Used: Thomas, Kelly.

Booked: Middleton.

Goals: Nugent 19.

Att: 13,296

Ref: J Winter (Stockton-on-Tees).