IPSWICH TOWN 1, NORWICH CITY 5: The Canaries completed the most astounding of derby day doubles with another comprehensive thumping of the old enemy on Thursday.

Having beaten Town 4-1 at Carrow Road in November, they went into the lion's den, and roared their way to another mauling. It could have been more, but in the context of the season, three points and a massive confidence booster will do nicely, thanks.

Andrew Surman gave City the ideal start after 13 minutes, before Gareth McAuley's awful run against the Canaries continued when he put the ball into his own net on 24 minutes.

McAuley, reportedly being watched by Glasgow Rangers, scored own goals in City's favour while playing for Leicester in the home and away games during the 2006-07 season and in December, 2008, while playing for Ipswich, was ordered off the field for treatment and could only watch as Matty Pattison scored the second Norwich goal in a 2-0 home win.

Simeon Jackson added a third after 73 minutes – his fifth in five games and ninth of the season – before Jimmy Bullard pulled one back five minutes later from long range.

It tested the nerves for a matter of two minutes, with Russell Martin hitting City's fourth and substitute Dani Pacheco making it five in time added on to give City derby rout number two of the season.

City were dead and buried the last time they set foot on Portman Road – in April 19, 2009 – a 3-2 defeat left them in the relegation zone with two games to play. No one of either hue needs reminding what happened, but who has actually improved most since that day? Clearly, it's City who, under Paul Lambert, are a club transformed. Last night was just another chapter in his remarkable Norwich City story.

Lambert kept faith with the starting line-up, and bench, which faced and beat Nottingham Forest on Friday, while Paul Jewell was forced into one change, Jason Scotland starting ahead of Lee Martin, who was beginning a three-match suspension, while midfielder Grant Leadbitter had recovered from the head injury sustained at Bristol City on Saturday.

Some early loose balls from Ipswich perhaps betrayed a few nerves, although Scotland almost got a touch in the area before Zak Whitbread cleared.

Scotland had the first effort on target, beating Ward on the right, cutting in and shooting left-footed, although John Ruddy gathered it with ease.

City midfielder David Fox went into the book on 10 minutes for a foul on David Norris – he would spend the rest of the game taking extra care.

Moments later the crowd saw Connor Wickham in full flow for the first time, the teenager picking up a Scotland flick-on, making it into the area, but then firing wide of Ruddy's right-hand post – Martin had done enough to keep him wide and at a difficult angle.

Leadbitter tried his luck from 30 yards – Ruddy watched the ball go past his right post.

Then on 13 minutes City got their big break. Marc Tierney played the ball inside to Andrew Surman, who played it wide to Hoolahan. His low cross was only parried away by former Canaries youth team keeper Arran Lee-Barrett and Surman was there to fire right-footed from some 10 yards. City were worth the lead, without a doubt.

At the other end the pacy Simeon Jackson, who was causing Town all sorts of problems, was denied a goal by an excellent tackle by Damien Delaney, but from the resulting corner the ball went past everyone – except McAuley who, facing his own goal, could do nothing to prevent the ball hitting his leg and going into the back of the net.

Lucky it may have been, but City were on fire, passing the ball well and frightening the Tractor Boys' back four. 'There's only one Keano,' sang the travelling fans, a reference to former Town boss Roy Keane – followed, inevitably, by 'There's only one Paul Lambert.'

Crofts, Hoolahan and Fox were working their socks off to stifle anything the Town midfield attempted – and when it broke, City broke well.

Grant Holt was putting in a shift, too, and almost benefited when Delaney made a mess of a back header, the City skipper nipping in and only being denied by the sprawling arms of Lee-Barrett – but once again it was Jackson who put the fear of God into the back four.

With half-time approaching, Holt looked to be having words with left-back Darren O'Dea who, if he didn't leave a foot in on the right touchline appeared to leave an arm. Referee Jon Moss spotted the difference of opinion and had words, although that didn't stop Holt, who chipped away as they went off at the interval, with Lambert perhaps having words as well.

Half-time came and went in a blur – of yellow and green.

Bullard almost gave Ipswich some hope less than two minutes in, but volleyed inches wide, while half-time substitute Andy Drury fired wide minutes later. City would have expected nothing less by way of a response. Jackson almost freed Hoolahan, but O'Dea had enough muscle to keep him out. Surman then played Crofts in for a first-time effort from the edge of the area which landed on the top of the net.

Once again Ipswich had the bulk of the possession, but once again they were restricted to long-rangers, Leadbitter side-footing one wide.

But for all their hard work, Ipswich were undone by something simple. Holt – who looked to be having a few problems with fitness – sprang into life down the right, beat Delaney all ends up, put in a low cross and Jackson got in front of McAuley to poke the ball home.

It was perfect in its execution – 'Are you watching, Carrow Road' sang the green army – no doubt the beam back fans were in equally high spirits.

They were briefly silenced five minutes later when Bullard fired a cracking long-range effort into the top left-hand corner to give Town some hope.

But amazingly, on 80 minutes it was game over – Hoolahan breaking down the left and, with Jackson and Martin to choose from, playing it long, behind the retreating Ipswich defenders to the back of the area where Martin fired under Lee-Barrett.

It was the perfect example of a breakaway goal.

Holt made way for Vokes on 83 minutes – to boos from the majority, who were drowned out by the minority. It was all over for the boys in blue. So demoralised was the home defence that when Jackson hit the woodwork, Pacheco had all the time in the world to ram home number five to register his first senior goal in English football following his loan switch from Liverpool.

Within seconds of the final whistle, virtually all that was left inside Portman Road was a corner of excited Norwich City fans who will now be praying that leaders QPR can do them a favour tomorrow when they visit Cardiff, the main threat to the Canaries' bid for automatic promotion. The Bluebirds will go into that match in third place after last night's drama – but will move back up to second if they beat Neil Warnock's side. Anything less than three points and City will be guaranteed promotion if they win their final three matches, starting at home to Derby on Monday.