The Canaries' victory sent them four points clear in second place and provided a stark reality check for new Iron boss Alan Knill, who saw his increasingly doomed side sink to the foot of the table.

Holt opened the scoring after 10 minutes and added his second - and his 50th goal for the club - from the spot in the 32nd minute after being pulled down by Paul Reid, who was sent off.

The 10-man visitors proved no match for the rampant home side with Holt netting his third on 61 before it was Jackson's turn to finish off a profitable afternoon with a treble of his own in the last 15 minutes.

The Canaries' day was made better by the news that Swansea, who started the day in third place, had slipped to a shock 2-1 defeat at Preston, whose unlikely survival bid continues to gain momentum.

Seemingly doomed a month ago, Phil Brown's men have now won three in a row and they had Iain Hume to thank for their win over the below-par Swans.

Hume opened the scoring with a third-minute penalty and, despite an Ashley Williams header bringing the visitors level on 24, Hume scored the winner seven minutes from time after a brilliant mazy run.

Cardiff took full advantage of their Welsh rivals' slip-up as they hammered Derby 4-1 to take over in third place.

Jay Bothroyd gave the Bluebirds a seventh-minute lead from the spot and Dekel Keinan added a second three minutes into the second half.

Paul Quinn and Peter Whittingham added second-half goals for the home side, before Robbie Savage grabbed a consolation goal for Derby with an injury-time penalty.

In an early kick-off, Simon Grayson's Leeds further secured their own play-off berth and sent Nottingham Forest tumbling out of the top six with a 4-1 win at Elland Road.

Forest had Chris Cohen sent off on 36 minutes for violent conduct and after the break the home side dominated with Jonny Howson and Luciano Becchio putting them 2-0 up by the hour.

Garath McCleary briefly reduced the deficit for Billy Davies' men, but a late double from Max Gradel secured Leeds' position in fifth place, four points above Reading one place below.

The Royals continued their fine recent form with a 2-0 win over Portsmouth at the Madejski Stadium, with Shane Long grabbing both goals in the first half.

Millwall took full advantage of slip-ups by other play-off contenders to move within three points of the top six after Steve Morison's 33rd-minute effort was enough to earn the points at Hull.

Burnley were undone by early goals from David Norris and Conor Wickham as they lost 2-1 at home to Ipswich, while Watford lost 2-0 at struggling Coventry.

Crystal Palace gave their survival prospects a huge boost with a 2-1 win over Barnsley to move five points clear of danger. Neil Danns and James Vaughan sandwiched a Marlon Harewood strike.

Former Middlesbrough star Ayegbeni Yakubu came back to haunt his former club as he hit a hat-trick for Leicester in an entertaining 3-3 draw at the Riverside Stadium, Stephen McManus equalising in injury time for the home side.

Nicky Maynard struck a 76th-minute winner for Bristol City at home to Doncaster, who slip closer to the drop zone as a result.