Brazilian striker Marcelo struck with an 81st minute equaliser to push Sheffield United a point closer to the promotion play-offs.

Marcelo rose unmarked at the far post to send a looping header past the despairing dive of keeper Fraser Digby following Wayne Quinn's centre from the left.

It was cruel luck on Swindon who had taken the lead through Mark Walters stooping header in the 33rd minute.

And the visitors were indebted to Republic of Ireland keeper Alan Kelly for keeping them in the game before Marcelo's late strike.

Kelly saved brilliantly with his legs to deny George Ndah four minutes before the interval and then produced a fantastic double save in the second half to keep out efforts from Ndah and Chris Hay.

Blades boss Steve Thompson was forced to make four changes from the side which drew 2-2 against Norwich on Saturday in their search to secure an end of season play off spot but the visitors started in lacklustre fashion and deservedly found themselves behind shortly after the half hour mark.

Walters collected a ball on the half-way line and spread play to Ty Gooden on the left before continuing his run into the penalty area.

Gooden delivered a pinpoint cross and then Walters provided the finish sending his header inside the left hand post for his sixth goal of the season.

Darren Bullock should have added a second eight minutes later after Kelly had performed wonders to keep out Ndah's low shot with his legs but Swindon continued to dominate in the second half and only the brilliance of Kelly kept United in the game.

Ndah raced down the right in the 50th minute before cutting into the penalty area and Hay looked odds on to score as the striker prepare to centre but Kelly was alert to the danger cutting out the cross.

And then a minute later after Walters had beaten full back Chris Wilder and picked out Hay at the far post Kelly was perfectly positioned to beat away the striker's header from five yards.

Defender Craig Taylor was unlucky not to extend Swindon's advantage with just ten minutes remaining when he saw his close-range header cannon off a post before rebounding to safety and Sheffield United took advantage of their luck for Marcelo to score with their next attack.

United could even have stolen the points in the 83rd minute following a mistake from the otherwise impressive Digby but Dean Saunders fired wide from 15 yards with the goal at his mercy.

Teams

Swindon: Digby, Kerslake, Davis, Taylor, Bullock, Borrows, Walters, Collins (Cuervo 64), Hay, Ndah, Gooden.

Subs Not Used: Cowe, Robinson.

Booked: Borrows, Gooden.

Goals: Walters 33.

Sheff Utd: Kelly, Wilder, Quinn, Ford (Dellas 79), Sandford, Holdsworth, Saunders, Marker (Derry 68), Devlin, Marcello, Stuart.

Subs Not Used: Katchouro.

Booked: Holdsworth, Devlin.

Goals: Marcello 81.

Att: 5,956

Ref: D Pugh (Wirral).