Kutuzov's southern advance had left his northern flank around the Abrax mines relatively understrength, but Kutuzov was expecting the Death Guard assault from that direction when it came. In response, the Dark Angels were on hand to deliver a lightning strike against the traitor HQ units. By attacking the elite forces of the enemy the Imperium hoped that the chaos advance would collapse, but the Death Guard defended stubbornly. After hours of hard fighting, the Dark Angels were forced to admit their mission had failed, and they withdrew, bitterly disappointed at how close they had come to halting the chaos assault.
The failure of the Dark Angels was soon felt by the Imperial line, which fell back before the Death Guard assault. By 1202.021M42 the traitor legion had reached the main Abrax complex which the Adeptus Mechanicus were attempting to purify and use for the imperial war effort. The Adeptus Mechanicus forces, though strong, were unable to resist the unrelenting advance of the Death Guard forces. Overwhelmed, the Mechanicum forces fell back, and Kutuzov now faced significant forces on two fronts.