Between 6 and 9 January, "Triumph" conducted pre-invasion sweeps of the assault areas in Lingayen Gulf. Though the main task force was subjected to incessant enemy air attacks, the minesweeper continued her mine-sweeping almost unmolested. Each night, she retired from Lingayen Gulf and took up screening station for the transports and cargo ships. On the 9th, the ground troops stormed ashore at Lingayen, and "Triumph" kept a close watch for enemy submarines and suicide boats. She remained in Lingayen Gulf until the 14th — riding at anchor during the last three days of that period — and then got underway with a Leyte-bound convoy of LST's and LCI's. After transiting the Sulu Sea, the Mindanao Sea, Surigao Strait, and Leyte Gulf, the Allied ships arrived in San Pedro Bay on the 19th.