In company with , "Guitarro" departed Fremantle 8 October 1944 for her third war patrol in Philippine waters. As the epochal Battle of Leyte Gulf developed, "Guitarro" played an important role. She sighted the Japanese Central Force under Admiral Takeo Kurita on the night of 23 October – 24 October and tracked the ships through Mindoro Strait, unable to close for an attack. Her contact reports on the force were vital to the success of the ensuing engagements, which by 26 October virtually eliminated the remaining Japanese naval forces in the Pacific.