Underway from Fremantle on 16 December 1942, she arrived off Soerabaya, Java, on 25 December. She intercepted a convoy of freighters, escorted by two destroyers, several subchasers, and two aircraft. Slipping past the escorts, "Thresher" sent five torpedoes towards the leading three ships. Two successive explosions followed. Rising to periscope depth, the boat observed the second ship in the column down by the bow, with her stern up in the air and her screws, still revolving, out of the water. A second ship lay dead in the water, enveloped in smoke. Escaping unscathed from this tangle with a coastal convoy, "Thresher" sighted an enemy aircraft carrier the next night, but was picked up by escorts and held at bay for more than an hour while the tempting target faded into the night.