"Bayan" was assigned to the First Pacific Squadron after completion, and based at Port Arthur from the end of 1903. She suffered minor damage during the Battle of Port Arthur at the beginning of the Russo-Japanese War and participated in the action of 13 April 1904, when Vice Admiral Tōgō Heihachirō successfully lured out a portion of the Pacific Squadron, including Vice Admiral Stepan Makarov's flagship, the battleship . When Makarov spotted the five Japanese battleships, he turned back for Port Arthur, and "Petropavlovsk" struck a minefield and quickly sank after a mine detonated one of her magazines. After bombarding Imperial Japanese Army positions on 27 July, "Bayan" struck a mine and was under repair for the next month or so. She was subsequently trapped in Port Arthur and sunk at her mooring by Japanese howitzer shells on 8 December.