Goals from Marvin Friedrich and Christian Gentner secured a magnificent away victory for 1. FC Union Berlin in Cologne.
Urs Fischer's squad took their Bundesliga points tally to 35 points – level with the Billy Goats. Friedrich's header on 39 minutes gave the Köpenick club confidence ahead of the interval.
Christian Gentner added his second league strike of the campaign, finishing off with a volley in the 67th minute.
Though Union were largely comfortable, Jhon Cordoba scored in stoppage time to make it a nervous closing few seconds for the visitors.
1. FC Köln: Horn; Ehizibue (Schindler 63), Bornauw, Czichos, Schmitz (Leistner 46); Shkiri (Höger 83), Hector; Uth, Drexler (Modeste 46), Kainz (Rexhbecaj 70); Cordoba
1. FC Union Berlin: Gikiewicz; Trimmel, Schlotterbeck, Friedrich, Reichel (Hübner 70); Gentner, Prömel; Ingvartsen (Mees 88), Malli (Kroos 63), Bülter; Andersson (Ujah 63)
Grischa Prömel, Ken Reichel and Marcus Ingvartsen were handed starts in Cologne in place of Florian Hübner, Anthony Ujah and the suspended Robert Andrich. Former Union defender Toni Leistner started on the bench for the Billy Goats, while Markus Gisdol was forced into a last-minute change as Dominik Drexler replaced Jan Thielmann. The fact both clubs pride themselves on a strong defensive foundation came as little surprise on the early exchanges at the Rhein-Energie-Stadion in Müngersdorf. Ingvartsen broke clear of the Köln defence after five minutes but mixed up his angles and dragged his shot wide of the target. After a few rocky results since the restart of the Bundesliga, Union looked solid and assured without the ball. The Köpenick club almost celebrated a breakthrough on 31 minutes when Martin Petersen pointed to the penalty spot. Sebastian Andersson's attempted cross from the right struck the hand of Rafael Czichos, but after Petersen double-checked at the monitor, he decided not to award the spot kick. What could have been a double negative for Union Berlin turned into a positive. Fischer's players put Timo Horn's box under pressure – Yunus Malli taking a heavy touch when presented with a shooting opportunity after 38 minutes. However, first blood in Cologne was drawn just a minute later when Friedrich earned a yard on his marker and powered a header past Horn from inside the six-yard-box to give Union a well-deserved lead at the interval.
Markus Gisdol wasn't pleased with his side's first-half display and made two changes at the break. Anthony Modeste's introduction changed the dynamic to Cologne's attack alongside Jhon Cordoba. Rafal Gikiewicz stepped up to the challenge and kept Union ahead with a couple of saves as Cologne took control. On 61 minutes, the Polish goalkeeper reacted quickly and saved well from Florian Kainz's shot at the back-post. Keven Schlotterbeck's last-gasp tackle on Cordoba a few moments later held the home side at arm's length. Fischer and his coaching team moved pro-actively to shuffle the pack with Ujah replacing Andersson and Felix Kroos stepping into a midfield role in the place of Yunus Malli. It was another midfielder who would put the icing on the cake after 67 minutes at the empty Rhein-Energie-Stadion. Marius Bülter's return long-ball came at a furious pace to Gentner who held his nerve, cushioned the ball down to himself and fired ruthlessly past Horn from close range. Union returned to their favoured back-three system with 20 minutes left as Reichel was substituted for Florian Hübner. With the bit between their teeth, Union defended confidently like we've seen on previous occasions under Fischer. The home side scored through Cordoba in the second minute of injury time to set the heart of Union supporters racing, but the victory was secured.
Three points better off, 1. FC Union Berlin return to home comforts and will look to take a huge step forward to survival. Urs Fischer's men welcome former Union player Steffen Baumgart back to the Stadion An der Alten Försterei when he brings his Paderborn side to the capital on Tuesday night.