The Battle of the Malacca Strait, sometimes called the Sinking of the Haguro, and in Japanese sources as the Battle off Penang, was a naval battle that resulted from the British search and destroy operation in May, 1945, called Operation Dukedom, that resulted in the sinking of the Japanese cruiser Haguro. Haguro had been operating as a supply ship for Japanese garrisons in the Dutch East Indies and the Bay of Bengal since 1 May 1945.

The Battle of the Malacca Strait, sometimes called the Sinking of the Haguro, and in Japanese sources as the Battle off Penang, was a naval battle that resulted from the British search and destroy operation in May, 1945, called Operation Dukedom, that resulted in the sinking of the Japanese cruiser Haguro. Haguro had been operating as a supply ship for Japanese garrisons in the Dutch East Indies and the Bay of Bengal since 1 May 1945.

On the 9 May, the Haguro left Singapore, escorted by the destroyer Kamikaze, to re-supply the Port Blair garrison on the Andaman Islands and to evacuate troops back to Singapore. The Royal Navy was alerted to this by a decrypted Japanese naval signal, subsequently confirmed by a sighting by the submarines HMS Statesman and Subtle. Force 61 of the Eastern Fleet set sail on 10 May from Trincomalee, Ceylon to intercept the Japanese flotilla.

Japanese Heavy Cruiser Haguro

On the 14 May, Haguro and Kamikaze tried again and left Singapore. Next day, they were spotted by aircraft from Force 61. The subsequent air attack caused only minor damage to Haguro, for the loss of an aircraft whose crew was taken prisoner by the Japanese.

Information was relayed to the Japanese that two British destroyer squadrons had been sighted heading towards them. Again, they reversed course to return to the Malacca Strait. This change had been anticipated, however, and the 26th Destroyer Flotilla (HMS Saumarez, Verulam, Venus, Vigilant, and Virago), commanded by Captain Manley Power (on the Saumarez) steamed to intercept. In heavy rain squalls with lightning, Venus made radar contact at 34 miles (54 kilometers). The British destroyers arranged themselves in a crescent cordon and allowed the Japanese ships to sail into the trap.

At 0105 Saumarez 4.7-inch (12-cm) guns opened fire at a range of 3 kilometers and hit Haguro with the second salvo. Saumarez turned sharply right to pass astern of Haguro and raked Kamikaze with Bofors 40 mm gun fire as the Japanese destroyer appeared off the port bow and swept by. Haguro returned six main battery salvos at Saumarez before being hit at 0115 by three torpedoes fired by Saumarez and Verulam. Venus hit Haguro with one torpedo at 0125 and Virago stopped Haguro with two more torpedo hits two minutes later. Haguro sank at 0209 after receiving another torpedo from Vigilant, two more from Venus, and nearly an hour of gunfire from the 26th flotilla.

Kamikaze was also damaged, but escaped, returning the next day to rescue survivors. About 320 survived but 900 died, including the Japanese commanders, Vice-Admiral Hashimoto and Rear-Admiral Sugiura.

RFA Eaglesdale and RFA Olwen (1) were engaged in support of this operation