Ljungberg (r) got the vital goal Photos from the semi-final

Arsenal 1-0 Sheffield United

Arsenal reached their third successive FA Cup Final by beating Sheffield United - but only after a highly controversial Old Trafford encounter.

Arsene Wenger's side stayed on course for a historic second successive double thanks to FA Cup talisman Freddie Ljungberg's first half winner.

But referee Graham Poll was the villain for Neil Warnock's brave First Division underdogs.

Poll failed to hold up play for an injury, then inadvertently blocked a Blades challenge, in the build up to Ljungberg's strike.

They were then denied by an astonishing late save from Arsenal goalkeeper David Seaman, who crowned his 1,000th senior appearance with a match-winning save from substitute Paul Peschisolido.

Arsenal's joy was tempered, however, by an injury to Patrick Vieira that could make him doubtful for Wednesday's title showdown wiht Manchester United.

It was vindication for Wenger, who restored Seaman, along with defender Martin Keown.

And Arsenal stuck with the tried and trusted policy of keeping strike pair Thierry Henry and Dennis Bergkamp on the bench.

The manner in which we have lost this match is an absolute disgrace Neil Warnock More post-match reaction

If the Blades plan was to knock Arsenal out of their usual smooth stride, it worked perfectly until the fateful intervention of Poll.

The game turned in seconds in the 35th minute, first when Poll waved play on after Wayne Allison tumbled under challenge from Sol Campbell.

Poll then blocked an attempted challenge by Michael Tonge as Arsenal broke forward.

Francis Jeffers crossed for Sylvain Wiltord, who struck a post from close range - but Ljungberg made no mistake after the France striker retrieved the rebound.

It sparked fury in the Sheffield United ranks and prompted angry gestures from boss Warnock as Poll made his way to the dressing room at half-time.

The First Division side created their clearest opening after 52 minutes when Michael Brown's surging run left Peter Ndlovu unmarked 12 yards out, but his finish was tame.

Arsenal suffered a setback three minutes later when Patrick Vieira, who was wearing a strapping on his knee and had been the victim of a heavy challenge from Michael Brown, limped off to be replaced by Gilberto Silva.

And just after the hour, the golden opportunity the Blades craved arrived - but was squandered.

HAVE YOUR SAY Whatever is said about the game, the goal, the ref, David Seaman in his 1000th professional game probably made the greatest save of all time! From Jarek Dylong Join the 606 debate

Midfield man Brown, with 17 goals this season, was clear in front of goal only 12 yards out, but screwed a finish agonisingly wide.

And Arsenal had an even bigger escape with six minutes left - when they were indebted to an astounding save from Seaman.

Subsitute Peschisolido looked certain to score when he diverted Carl Asaba's shot towards goal, but Seaman defied the years and Sheffield United with a one-handed save.

It was the last chance, and as in the Worthington Cup, Sheffield United had fallen at the semi-final stage again.

Arsenal: Seaman, Lauren, Keown, Campbell, Cole, Ljungberg, Edu, Vieira (Silva 56), Parlour, Jeffers (Henry 66), Wiltord (Bergkamp 81).
Subs Not Used: Taylor, Luzhny.

Sheff Utd: Kenny, Jagielka, Page, Curtis, Kozluk, Ndlovu, Brown, McCall (Asaba 60), Tonge, Allison (Montgomery 60), Kabba (Peschisolido 79).
Subs Not Used: Murphy, Kelly.

Attendance: 59,170

Referee: G Poll (Hertfordshire).