The veteran defender, a free transfer from Bramall Lane in January, was only on the pitch because of injury to Ryan Taylor but when Phil Jagielka handballed the 33-year-old coolly drilled home to give his side a crucial 2-1 lead.

Paul Jewell's side had taken a 14th-minute lead through Paul Scharner's left-foot volley but Jon Stead's header eight minutes before the interval put United in pole position to survive.

However, in a relegation race full of controversy following West Ham's escape with a £5.5million fine for irregularities over the signings of Carlos Tevez and Javier Mascherano there were a few more twists left and it was the Blades who suffered the deepest cut.

Substitute Danny Webber hit a post having beaten keeper Mike Pollitt in the second half and even the dismissal of Lee McCulloch for a second bookable offence in the 73rd minute could not save Neil Warnock's side.

In the first minute Lee McCulloch, playing just behind striker Emile Heskey, won a corner but when the cross came over Heskey could only balloon it over under pressure from Matt Kilgallon.

The Wigan players appealed for a penalty for a shove on the former England man but referee Mike Dean was unimpressed.

The relentless action was befitting of a relegation decider and Wigan continued to make all the early running, with Paul Scharner's speculative volley from 20 yards in the 11th minute floating wide of Paddy Kenny's right post.

It was a warning of what was to come as the deadlock was broken in the 14th minute.

Heskey picked out Kevin Kilbane on the left and his low cross was met first-time by Scharner from the edge of the penalty area and the ball flew past Kenny and into the net.

With West Ham at that point drawing against Manchester United the goal meant United and not Wigan occupied the final relegation place.

Scharner could have had another in the 23rd minute when Kilbane again fed Heskey, who drove into the area before crossing to the far post where the Austrian midfielder headed over.

Wigan suffered a huge blow in the 31st minute when captain Arjan De Zeeuw was forced off with what looked like a knee injury. He was replaced by Josip Skoko, which meant the dangerous Scharner had to drop back into defence.

But in the 37th minute the relegation picture changed again as United equalised - although it was not without cost to both sides.

Jagielka, playing at right-back, crossed from wide and Stead rose above the defence to head the ball past Pollitt.

The consequence of that was a sickening clash of heads between the goalkeeper and striker which resulted in both receiving lengthy treatment.

Right-back Taylor was also injured - more seriously than the rest - and he hobbled to the sidelines before being carried away on a stretcher.

Former Sheffield United defender Unsworth came on in his place.

The hosts could have had a penalty and a goal in the same incident in first-half injury time as McCulloch looked to have dragged Jagielka to the floor before Stead blazed wide from six yards.

Unsworth's first contribution was a late foul on Nade which earned a booking.

However, his second was more crucial as he drilled home a penalty late in injury time after Jagielka handballed an inswinging free-kick from the left by his former team-mate.

Warnock made an immediate change at the start of the second half, with Danny Webber replacing the injured Nade.

Kenny was first into the action, producing a superb one-handed save to deny Heskey's overhead kick from Denny Landzaat's corner in the 50th minute.

Bramall Lane was celebrating prematurely five minutes later when Stead's flick-on put Webber clean through and he poked the ball past Pollitt only to see it rebound back off a post.

Kilgallon had a half-chance in the 60th minute when Gillespie's long-throw was flicked on by Chris Morgan but his fellow centre-back could just not get over the ball.

The impressive Scharner then had to be alert to half-block a Stead shot after Michael Tonge's quickly-taken free-kick.

Morgan then rose highest to meet substitute Colin Kazim-Richards' corner but turned his header wide at the far post.

United were handed a glimmer of hope when the hard-working McCulloch was sent off in the 73rd minute for a second bookable offence after clattering into Tonge having been booked for dissent in the 55th minute.

United laid seize to the Wigan goal in the late stages, with Gillespie's right-wing cross grazing the crossbar and Tonge admirably staying on his feet in the penalty area when he could easily have gone down under a challenge.

Jewell said afterwards: "It was a great achievement for us and I feel a little bit sorry for Sheffield United - it's not nice for someone to celebrate when the other team get relegated.

"But I felt all week people were writing us off and they (Sheffield United) had it all to lose.

"We didn't need to look at Old Trafford (where relegation rivals West Ham beat Manchester United 1-0) we just needed to win ourselves today.

"We played well until we scored, slacked off and came back from bit of a blow to score on half-time.

"The second half was backs to the wall, it was a long road."

And former Bradford boss Jewell, who masterminded a last day survival with the West Yorkshire team seven years ago tomorrow, had a message for one non-believer.

He added: "The guy who threw his season ticket at me against West Ham (at the JJB Stadium on April 28 when Wigan lost 3-0) - I hope he's watching.

"We haven't shown enough resilience when we have come under pressure, we've thrown away too many points from leading positions - but we did today.

"The last 15-20 minutes were like the Alamo but we got bodies in the way and they (United) didn't have too many clear-cut opportunities.

"But tonight's not to talk about the game - it's about survival and it's very tough for this club to be playing in the Premier League.