Norwich City's 12-game unbeaten run has been brought to an end after yet another chaotic Carrow Road afternoon finished in a 4-3 defeat to Derby County – in an epic match delayed by a floodlight failure.

Ben Godfrey and Teemu Pukki had fired a totally dominant Norwich team 2-0 up inside 31 minutes and it looked like a rout could be on the cards, only for Chelsea loanees Fikayo Tomori and Mason Mount to bring the Rams level before the break.

However, Pukki fired the hosts back in front with nine minutes remaining, scoring his 15th league goal of the campaign – only for a bizarre delay to follow the goal, as one of the River End floodlights stopped working.

After a wait of almost 20 minutes, the game got back under way and Derby took their chance, with goals from Florian Jozefzoon and Jack Marriott inflicting just a second defeat in 20 league games on City.

Head coach Daniel Farke made two enforced changes to his starting XI, bringing in Onel Hernandez for the injured Emi Buendia on the right of midfield. Meanwhile it was Christoph Zimmermann coming in for injured left-back Jamal Lewis, with Godfrey moving to left-back.

Todd Cantwell had an early chance for City but couldn't get enough power on his header from a Hernandez cross from the left.

But there was an early scare as Zimmermann hauled back Jack Marriott in a foot race, earning a yellow card, from which Harry Wilson could only hit the wall.

Hernandez tested Scott Carson at his near post early as well and Tettey fired a left-footed shot just wide in the 17th minute as the hosts totally dominated proceedings.

Carson pushed another Hernandez shot away, Tomori made a timely interception to halt Pukki and Godfrey headed over before Norwich claimed the goal they deserved in the 25th minute.

It was triggered by a wonderful long pass from the left from Mario Vrancic, finding Marco Stiepermann in the right channel, who beat Tomori and crossed low beyond everyone – but Godfrey was charging in to smash home a low shot for 1-0 and his first league goal for the Canaries.

Eastern Daily Press: Teemu Pukki scored twice for City but it wasn't enough to prevent a 4-3 defeat to Derby Picture by Paul Chesterton/Focus ImagesTeemu Pukki scored twice for City but it wasn't enough to prevent a 4-3 defeat to Derby Picture by Paul Chesterton/Focus Images (Image: Paul Chesterton)

Timm Klose headed over two minutes later as Derby looked shell-shocked, before the hosts doubled their lead in the 31st minute.

It was Vrancic who started again, halting a Rams attack by robbing Wilson and charging forward, threading Pukki into the box, where City's top scorer slotted into the bottom-right corner to register his 15th goal of the campaign.

It all seemed to good to be true, with the visitors sitting deep and offering nothing in attack, but at 2-0 down Frank Lampard's team threw caution to the wind – and found an equaliser five minutes later.

Mount played a short corner to Jozefzoon and the winger's low cross was nudged unfortunately by Pukki into the path of defender Tomori, who powered a rising shot in off the bar from 15 yards, giving Tim Krul no chance.

City's number one sprawled bravely at the feet of Marriott just a minute later, after the striker skinned Zimmermann for pace, and Max Aarons and Zimmermann both had to make timely interceptions as the Rams rampaged forward.

That brought an equaliser in the second minute of added time, after Wilson's corner from the right was only nodded as far as Mount on the edge of the box, where the England Under-21 midfielder lashed home through a crowded box.

That left the score at 2-2 and the Carrow Road faithful unsure where to turn after yet more mayhem had followed the 3-3 Boxing Day thriller with Nottingham Forest.

It was a far scrappier start to the second half as both teams seemed to tense up, and it wasn't until just after the hour mark when another big chance arrived, with Godfrey doing well to deflect a Marriott shot behind.

From there it was mostly City on the front foot but not able to force the issue. Vrancic made a superb interception in the 78th minute and exchanged a one-two with Hernandez but couldn't get any power on his low shot from the edge of the box, with an off-balance Alex Tettey lashing over two minutes later after strong play from Stiepermann.

And it was that man Stiepermann again with a wonderful high pass down the left wing to free Hernandez in the 81st minute. The winger looked like he'd wasted his chance after turning inside, but hooked a shot across the face of goal and Pukki was there to slot home at the back post at the Barclay end.

That was just the start of the drama though, as one of the Carrow Road floodlights went off in the aftermath and the players were called off the pitch by the referee – leaving the crowd wondering what was going to happen.

After around a 20-minute delay with spectators unsure of what was happening, the floodlight fired up again and the players soon followed – with the game to restart in the 82nd minute.

Both teams made substitutions and after a scrapy restart, the visitors drew level again within three minutes, to groans around the stadium.

Duane Holmes skipped away from Tom Trybull and played David Nugent in on the right, his low cross caused chaos and Jozefzoon charged in at the back post to slam home for 3-3.

City were rocking and a Mount cross-shot from the left again caused pinball in the home penalty area, only for Timm Klose to clear at the vital moment.

It was only temporary respite though, as Zimmermann miss-kicked a clearance in the 90th minute and Marriott tore through on goal and dinked over the exposed Krul.

As five minutes of added time began a cross from Godfrey on the right was just taken off the head of Dennis Srbeny by Aarons and the ball looped beyond the far post.

There was one final push for an equaliser though, with Carson making an amazing diving save to deny a Cantwell shot destined for the back of the net.

Tettey hurried over the corner and chaos ensued in the fifth minute of injury-time, with Jordan Rhodes slamming a shot against the underside of the crossbar but seeing the ball bounce agonisingly the wrong side of the goal-line.

It was drama in every sense of the word but eventually the Canaries' unbeaten run was brought to an end at 12 matches, as the home faithful applauded their players after another afternoon of mayhem.

Norwich are straight back into action on Tuesday, when they travel to west London on New Year's Day to take on mid-table Brentford (3pm kick-off).

Norwich: Krul; Aarons, Zimmermann, Klose, Godfrey; Tettey (C), Vrancic (Trybull 83); Hernandez, Stiepermann (Srbeny 89), Cantwell; Pukki (Rhodes 85). Unused subs: McGovern (GK), Pinto, Hanley, Marshall

Booked: Zimmermann (foul on Marriott, 5), Aarons (foul on Wilson, 45+4), Vrancic (foul on Jozefzoon, 62)

Goals: Godfrey (25), Pukki (31, 81)

Derby: Carson; Bogle, Keogh (C), Tomori, Wisdom (Nugent 82); Wilson, Evans, Mount; Waghorn (Holmes 78), Marriott (Bird 90+4), Jozefzoon. Unused subs: Roos (GK), Pearce, Bryson, Huddlestone

Booked: Evans (foul on Vrancic, 66), Wilson (foul on Aarons, 90+2), Holmes, foul on Aarons, 90+2)

Goals: Tomori (36), Mount (45+2), Jozefzoon (84), Marriott (90)

Referee: David Webb (Lancs)

Attendance: 26,886

• Follow all the post-match reaction and analysis from Carrow Road in our Matchday Live blog at pinkun.com/live