They were also able to successfully land 1,200 ground troops on the western coast of Kolombangara but lost one light cruiser sunk in the process.

The Allied campaign in New Georgia had begun on 30 June 1943 as part of their advance through the central Solomon Islands towards Rabaul under the guise of Operation Cartwheel.

[4] In response to the Allied landings, the Japanese sought to reinforce New Georgia to shore up the southern flank to their base around Rabaul.

[5] On the night of 12 July a Japanese "Tokyo Express" naval reinforcement force made a run down "The Slot" from Rabaul to land troops at Vila on Kolombangara by way of the Kula Gulf.

It consisted of two United States Navy light cruisers, USS Honolulu and St. Louis and the Royal New Zealand Navy light cruiser HMNZS Leander, and the destroyers USS Nicholas, O'Bannon, Taylor, Jenkins, Radford, Ralph Talbot, Buchanan, Maury, Woodworth, and Gwin.

[9] Ainsworth's mission was to prevent Japanese troops and supplies from landing as part of efforts to stem the flow of reinforcements towards Munda.

His plan for the attack was to use the first squadron of five destroyers that formed his vanguard to fire torpedoes while his cruisers maneuvered into a position to use their main guns.

[12] As the skies began to grow overcast at 01:00 on 13 July, the Allied ships established radar contact about 20 mi (17 nmi; 32 km) east of the northern tip of Kolombangara at 7°50′S 157°21′E / 7.833°S 157.350°E / -7.833; 157.350.

After losing steerage around 01:17, Jintsū came to a dead stop, was reduced to a wreck, broken in two by several torpedo hits, and sank at about 01:45, with the loss of nearly her entire crew including Isaki.

[15] Amidst the confusion of the initial battle, Ryan's destroyer squadron began its torpedo run from a distance of 7,900 yards (7,200 m), firing his first salvo around 01:12.

As a result, Ainsworth requested air support, and a strong fighter force was provided from bases in the Russell Islands to cover the withdrawal.

"[26] Paul Dull further describes the battle as one in a "series of Pyrrhic victories for the Japanese" as they were unable to match the capacity of U.S. industry to replace their losses.

[27] Ainsworth's force was unable to prevent the flow of Japanese reinforcements south as the lines between Bairoko and the Diamond Narrows remained open.

The Allied naval commander, Admiral Chester Nimitz, also changed tactics, deciding that the use of cruisers in the confined waters around the Solomon Islands was too dangerous and ineffective.

Meanwhile, for the Japanese destroyer losses necessitated the use of Daihatsu barges to move reinforcements between the Shortland Islands and the Kula Gulf.

[29][30] Throughout July and into early August, a series of nightly actions took place involving by U.S. destroyers, PT boats and aircraft against the Japanese reinforcement efforts.

The most significant action during this time came on the night of 19/20 July, when a force of 11 ships, consisting of cruisers and destroyers under Rear Admiral Shoji Nishimura, was detected by U.S. aircraft in The Slot.