Hamburg made it two wins from two after a ruthless showing at a Cologne side who had the lion's share of the play. The substitute referee showed a red card in his first action while German app viewers slammed Eurosport.
Cologne 1-3 Hamburg
Sorensen 90+7; Hahn 28', Wood 34', Holtby 90 + 10', Mavraj sent off 59'
Hamburg moved top of the Bundesliga for the first time since September 2009 after producing the sort of composed performance which long-suffering fans had forgotten they were capable of.
Last season’s strugglers triumphed after Andre Hahn scored with his first shot for the club and Bobby Wood also capitalized on hesitant Cologne defending in the first half, before Frederik Sorensen and Lewis Holtby traded goals late on.
Holtby’s strike, on 99 minutes and 54 seconds following a flying Hamburg counterattack, was the latest Bundesliga goal since detailed Opta collection of data began in 2004/05.
This was because of 13 minutes injury time added on not for a player, but for referee Felix Brych who had to leave the field early in the second half.
His replacement, the fourth official Sören Starks, then handed Hamburg’s Mergim Mavraj a second yellow card in his first meaningful action as the man in charge. It was a justifiable booking for a shirt tug by the former Cologne defender.
Hamburg defended doggedly after the setback and Christian Mathenia made some good saves in goal as they backed up last weekend's 1-0 win over Augsburg, when they lost talisman Nicolai Mueller to a freak injury.
The hosts had most of the play on Friday but Hamburg showed a ruthlessness that Cologne were again sorely lacking having let go of star striker Anthony Modeste.
While angry German viewers of the Eurosport App were having trouble seeing the company’s first exclusive live game because of technical problems, Cologne were struggling to kickstart their season after an opening 1-0 loss to Borussia Mönchengladbach in the Rhine derby.
Perhaps the home side were put in a somber mood by their tough Europa League group stage draw earlier, which pitted them against Arsenal, Red Star Belgrade and BATE Borisov.
Either way, they looked a shadow of the side who finished fifth last term with Jhon Cordoba again trying hard but not looking anywhere near an effective replacement for Modeste.
The Colombian did strike the outside of the post in one foray but Cologne fans will be hoping the club brings in another centre forward before the transfer window shuts next week.
See below for the live blog of the match
ALL OVER. HAMBURG HAVE WON 2 OUT OF 2.
Great work from Diekmeier to set up Holtby. Game over surely. Or it may have been Ekdal, apologies it is getting frantic
90 + 10 GOAL: Holtby makes it 3-1 to Hamburg
Sorensen's goal from a tight angle was checked by the video assistant and was OK
90+9 Yellow for Hamburg's Papadopoulos
There are around six minutes of injury time left (referee was hurt)
90+7 GOAL: Sorensen cuts the deficit.
90+ Holtby on Kostic off for Hamburg
90 - But remember we have a good nine minutes injury time to play...for the referee!
88 - Yellow card for Hector
85 - Hamburg's Mathenia making some great saves late on
77 - Cologne really putting the pressure on now, Cordoba denied by Mathenia
A Cologne staff member had to hold the board aloft, the fourth official is on the pitch!
72 - Cologne's final substitution sees Matthias Lehmann make way for Milos Jojic
71 - Hamburg's Diekmeier booked for time-wasting
67 - 10-man Hamburg now dropping back and trying to slow down the game
61 - Hamburg coach Gisdol responds by taking off Waldschmidt and bringing on Yung. Waldschmidt was a sub earlier for the injured Hunt!
This game is getting increasingly bizarre. But it was a yellow I would say. Some officials would not have shown another yellow as he was on one already but rules are rules.
A second booking for the Hamburg man
59 - RED CARD: First action of new referee is to send Mavraj off!
About nine minutes of play lost there due to the referee's injury. Sören Starks now in charge
51 - Felix Brych is going to have to come off. Will the Video Assistant now do the whole game? ;) No, a fourth official will do the job.
49 - Now the referee is injured!
48 - Cordoba hits the outside of the post! He can't get a break
46 - Back underway for the second half. Sehrou Guirassy replaces Bittencourt for Cologne
Halftime. I did not expect that. Ruthless from HSV but this could be a long hard season for Cologne with the Europa League as well. Can they get back into it? Shame no Modeste or any prolific striker on the bench.
45 - Wood almost makes it 3-0 but Sorensen is on hand to clear
42 - Cologne almost hit back but Hector's effort is deflected onto the crossbar
Hamburg meanwhile can't believe it, heading for two wins from two but it is still the first half.
What a terrible start to the season this is turning ou to be for Cologne. And they were given a really tough Europa League draw earlier too
A freekick was swung in which Cologne failed to clear. Waldschmidt passed to Wood who scored from close range
34 - GOAL for Hamburg. Bobby Wood
29 - But we have another injury, this time for the visitors. Hunt off, Waldschmidt on
The new Hamburg forward drives the ball into the net following a corner.
28 - GOAL for Hamburg. Andre Hahn
In fairness to Eurosport, we have not heard from them what the issue might be. But the DFL has a big problem if first the video assistant referee system malfunctioned last weekend and now this.
25 - The hosts on top but it looks like an injury. Marcel Risse makes way for Christian Clemens.
22 - Cordoba unleashes a shot but it can't get through a crowd of bodies. You feel for him. He is trying hard but is he really Modeste's replacement?
20 - Not a lot of goalmouth action. It is about even so far.
Today is the first time Eurosport have sole TV rights in Germany for a Bundesliga game. Some fans already complaining on social media that the Eurosport-Player online is not working properly.
11 - Sorensen now with a yellow card for the hosts
10 - Both sides with half chances so far, Osako with the best for Cologne. Good save by Mathenia
3 - Former Cologne player Mergim Mavraj gets an early booking for Hamburg
We have kicked off in the Rhein Energie Stadion.
Here are the teams