Norwich City 6, Scunthorpe United 0

Holt's treble took him to 51 career goals for the Canaries and Jackson added a remarkable hat-trick of his own in the space of 15 minutes to wrap up a comprehensive victory over relegation-threatened Scunthorpe United in front of Carrow Road's second biggest crowd of the season.

It was the most one-sided game seen at Norwich for many a season and there was a party atmosphere inside the stadium even before Jackson's 70th-minute introduction.

Defeat for promotion rivals Swansea at Preston made it an even better afternoon for Paul Lambert's men, who opened up a four-point gap over Cardiff City in third place with a veritable goal feast.

It was the first time two City players scored hat-tricks in the same match since Malcolm Allen bagged four and Robert Fleck three in the 8-0 FA Cup win over Sutton United in 1989.

It took just 10 minutes for City to move ahead, Holt poking home from a cross by Spanish Under-21 international forward Dani Pacheco.

And he reached 20 for the season on the half-hour when he scored his third penalty in four matches after being chopped down by Scunthorpe's Paul Reid, who paid the price with an instant red card.

The spot-kick was Holt's 50th goal for the club on only his 85th appearance, the second fastest half-century in club history after 1950s centre-forward Ralph Hunt.

He completed his hat-trick with just under half an hour remaining when he headed home from a centre by Andrew Crofts.

Jackson then got in on the act by ending a wait of more than five months for a goal, scoring twice in as many minutes.

He grabbed his first after 75 minutes after dispossessing Michael Raynes, then struck again when he tucked home a cross from fellow substitute Henri Lansbury.

Canadian international Jackson completed his hat-trick in the third minute of stoppage time when he diverted Andrew Surman's centre into the net.

Scunthorpe slipped to bottom of the table after Preston's victory.

Manager Paul Lambert put Pacheco, on loan from Liverpool, straight into his starting line-up at the expense of Henri Lansbury, who was relegated to the substitutes' bench after the 1-1 draw with Hull.

Striker Sam Vokes, on loan from Wolves, was also named among the substitutes, with full-back Adam Drury omitted from the 18 on duty at the KC Stadium.

Scunthorpe, under new management after the appointment of Alan Knill on Thursday, were captained by ex-Canary centre-half Michael Nelson, returning to Carrow Road after his deadline day move in January, with another former Norwich man, Andy Hughes, in the side at right-back.

Goalkeeper Joe Murphy was back after three months on the sidelines with an ankle injury, while loan signing Ramon Nunez, from Leeds, was in the starting eleven.

Scunthorpe won a free-kick in the opening minute but Ruddy safely gathered the kick from O'Connor.

Pacheco was involved early on as he moved on to Surman's pass and swung in a cross that Nelson cleared at full stretch before Holt could pounce.

Tierney then sent a long-range effort narrowly over the bar with keeper Murphy backpedalling.

Crofts was further off target with an ambitious shot from some 40 yards in the sixth minute.

Nelson made another timely interception to stop Holt cashing in on great work by Hoolahan, but in the 10th minute, the City skipper was not to be denied as he tucked away his 19th goal of the season.

Pacheco played a key role in the goal as he played a one-two with Surman before pulling back the cross for Holt to toe-poke his shot past Murphy, the 'keeper managing to get a touch but not enough to make a difference.

Two minutes later it was nearly 2-0 as Pacheco played another one-two with Surman and rolled his shot just the wrong side of the post from a tight angle.

Nunez looked lively for Scunthorpe and was perilously close to levelling in the 19th minute when his powerful drive took a faint touch off Ward and narrowly cleared the bar.

With City playing some polished football, Surman struck a powerful first-time shot just across the face of goal midway through the half after an astute pass by Hoolahan left him in space on the left.

Hoolahan, given plenty of space, was next to don his shooting boots with a well-struck effort from 30 yards that Murphy dived to his left to push round the post.

Nunez had Ruddy stretching to gather a cross at the far post in Scunthorpe's next attack, then Nolan floated in a centre from a similar position and Ruddy held on with Garner lurking behind.

On the half-hour, Scunthorpe's cause looked hopeless as they were reduced to 10 men and went 2-0 down to a Holt penalty.

Pacheco played Holt into a scoring position inside the Scunthorpe area, where he was unceremoniously chopped down by Reid.

Referee Langford pointed straight to the spot and produced the red card for Reid.

Holt stepped up to blast the penalty confidently past Murphy, his third spot-kick in four games, his 20th goal of the season and his 50th for the Canaries, on his 85th appearance.

Scunthorpe boss Knill responded by taking off their most effective player, Nunez, and replacing him with midfielder Togwell.

Hoolahan showed a touch of magic five minutes before the break as he turned on a sixpence and played a one-two with Crofts before hitting a swerving 20-yard shot just over the top.

Holt volleyed over the top as the interval approached – not too far away from completing a first-half hat-trick.

• HALF-TIME: Norwich City 2, Scunthorpe United 0

Pacheco had the first shot of the second period but was a yard wide after a patient build-up involving half a dozen of his team-mates.

Hoolahan showed more brilliant footwork to lose Raynes just outside the penalty area before letting fly with a powerful shot that was blocked by Togwell.

Hughes earned ironic cheers for stooping to chest a cross back to Murphy, but City were soon threatening again when Pacheco robbed Nelson and tried to float the ball in from fully 45 yards, Murphy getting back to collect.

Another seemingly never-ending passing move ended when Pacheco picked out Russell Martin and the full-back whistled a centre across the face of the goal.

There was a party atmosphere inside the stadium with Scunthorpe barely able to get a touch but City not quite able to create that clear-cut chance.

An error by Nolan led to a corner and when the ball reached Hoolahan, he struck a powerful shot that hit the post.

The third goal City had threatened came in the 61st minute, however, when Holt completed his hat-trick.

Holt managed to elude Nelson to score with the simplest of headers from a cross from the right by Crofts.

Scunthorpe made another change with Duffy replacing Collins and when Hoolahan suffered a knock to his hamstring, he made way for Lansbury.

Pacheco curled a marvellous attempt just wide after good work by Holt and, with 25 minutes to go, the skipper made way for Vokes to make his debut.

Scunthorpe made their final change a minute later when Dagnall came on for Garner.

Tierney almost made it 4-0 with a shot that Murphy pushed round the post and, while City waited to take the corner, Lambert made his final change by replacing Pacheco with Jackson.

As the onslaught continued, Vokes poked a shot wide after a one-two with Crofts, but the flag was up for offside.

Duffy sliced a shot into the crowd from Nolan's cross as Scunthorpe carved out a rare opportunity.

Vokes almost cashed in on a Lansbury through-ball but his control let him down at the crucial moment.

But it was 4-0 with a quarter of an hour left as Jackson scored his first goal since October.

Raynes was caught in possession by Jackson as he tried to control Togwell's pass and the substitute advanced before coolly nudging the ball out of Murphy's reach.

Two minutes later, Jackson stuck again when he tucked home Lansbury's cross at the near post.

Lansbury was involved in everything and his curling shot brought Murphy into action once again.

Ruddy was brought into action two minutes from time when he tipped a remarkable effort from O'Connor, from the halfway line, over the top to guarantee City's first clean sheet at home since New Year's Day.

Jackson missed one chance of a hat-trick in stoppage time when he headed wide from Lansbury's cross.

But he made amends on the stroke of time when he diverted a Surman centre into the net for his treble.

• RESULT: Norwich City 6, Scunthorpe United 0