On the morning of 10 August 1904, Dewa's cruisers were over south of Tōgō's 1st Division when the Russians sortied from Port Arthur in another attempt to reach Vladivostok. In the early stages of the battle, Dewa attempted to engage the Russian cruisers trailing the battleships in accordance with Tōgō's standing orders, but was rebuffed by fire from the battleships. As Dewa closed with the Russians later in the afternoon in another attempt to attack the Russian cruisers, a shell struck "Yakumo" amidships at 15:40, killing 12 and wounding 11. The range at this time exceeded , beyond the range of any gun in his squadron, so Dewa ordered his ships to disengage. By 17:45, "Yakumo" had maneuvered to about from the damaged Russian battleship "Poltava" and opened fire. "Yakumo" continued to close until the Russian squadron was thrown into confusion by the death of Vitgeft around 18:40.