Struggling Scunthorpe United were left to count the cost of a shocking start as they crashed to a sixth defeat of the season at Glanford Park.

They never recovered from conceding twice inside the opening 20 minutes as the Owls recorded a first win on Iron territory in more than 53 years.

The game was over by the time Jermaine Johnson added to Chris O'Grady's brilliant brace in the early stages of the second half.

And though Scunthorpe improved for the final 40 minutes, during which time striker Jordan Robertson headed home his first goal for the club, never did they look like fighting back to extend their unbeaten start to 2012.

The Iron were temporarily down to 10 men when the Owls struck the first blow.

Straight from the kick-off, on-loan full-back Christian Ribeiro took a bang on the head and needed extensive treatment, before later being replaced by Andrew Wright.

By the time the substitution was made, Wednesday were in front.

The ball that found O'Grady in the box was too simple and the former Rochdale front man made the most of being afforded an acre of space to turn and ram a shot between the legs of Sam Slocombe.

It was exactly the sort of start Scunthorpe didn't need.

And though heads did not really drop in the immediate aftermath of the setback, rarely were the hosts able to piece together anything that could be branded a decent spell of possession in the opposition third.

The same could not be said for Wednesday.

Every time the Owls ran at the home defence, they did so with intent and with a physical presence that the Iron struggled to combat.

They doubled their lead in the 18th minute, from Liam Palmer's left wing corner.

He swung the ball into the back post and though O'Grady's leap was majestic, the fact no United player challenged him as he nodded low into the net was unforgivable.

The best Scunthorpe could muster at the opposite end of the field were a couple of long range efforts, which did little to test visiting keeper Stephen Bywater.

Instead, it was Wednesday whose presence was prominent and twice more O'Grady almost added to his increasing tally before the break, once with a scissor kick that dropped wide and another shot on the turn which Slocombe swiped at.

The Iron's start to the second period was equally as frustrating as the first.

But whereas Wednesday's power had been the difference in their earlier dominance, it was the pace and trickery of Jermaine Johnson that paved the way for his side's third goal two minutes after the restart.

The Jamaican winger picked up possession midway inside the home half and ran around three Iron challenges before despatching the ball low into the corner from a reasonably tight angle.

Alan Knill responded by making two changes, sending on Mark Duffy and Bobby Grant for the ineffective Michael O'Connor and Andy Barcham.

From a left-wing corner, in the 55th minute, they gave themselves a lifeline, when former Sheffield United trainee Robertson – back in the starting line-up after a hip injury - stooped to head home Josh Walker's centre.

It signalled the start of a much brighter closing 30 minutes for the Iron, for whom Robertson was a threat and Duffy industrious, albeit with not much of an end product.

The best chance of the half though still fell to the Owls, with Slocombe brilliantly denying O'Grady a hat-trick by clawing away his angled drive one-handed, after a shot from Johnson had rebounded to him inside the area.

SCUNTHORPE: Slocombe; Ribeiro (Wright 4), Reid, Canavan, Nolan; Togwell, Walker, O'Connor (Grant 53); Thompson, Robertson, Barcham (Duffy 53). Subs not used: Lillis, Mozika.

SHEFFIELD WEDNESDAY: Bywater; Otsemobor, Batth, Llera, D Jones (Beevers 38); Johnson (M Jones 90), Semedo, Lines, Palmer; O'Grady, Madine (Morrison 89). Subs not used: Weaver, Lowe. 

ATTENDANCE: 5,727 (2,179 away).

Pictures: Scunthorpe Utd 1 Sheffield Wed 3

Iron's defending gives Knill sleepless nights