As the Japanese Mobile Fleet was turned back in defeat from the Marianas in the Battle of the Philippine Sea 19 to 21 June, Irwin shot down an enemy torpedo bomber while repelling air attacks on the escort carriers.

She assisted in the escort of the bomb-damaged cruisers Houston (CL-81) and Canberra (CA-70) to safety, then again joined the screen of fast attack carriers giving direct air support to the liberation landings at Leyte, 20 October 1944.

In a heroic saga that brought Irwin the award of the Navy Unit Commendation, she braved raging flames, violent explosions, falling debris, and exploding shells as she went alongside Princeton.

Later, when an explosion blew off the major portion of the carrier's stern, Irwin immediately dispatched boats and some of her men dove into choppy seas to rescue survivors.

For 2 months, Irwin bombarded enemy artillery positions, machine gun emplacements, troop concentrations, caves and suicide boat hiding places.

Irwin figured in another mercy mission the night of 16 June 1945 when she assisted in the rescue of survivors from destroyer Twiggs (DD-591), sunk by combined air, torpedo, and suicide attacks.

She entered Tokyo Bay 31 August and escorted occupation troops between Okinawa and Japan until 28 October when she stood out of Yokosuka for return to San Diego, arriving 15 November 1945.

Steaming through the Panama Canal, Irwin called at San Diego and Hawaii en route to join the 7th Fleet in waters off embattled Korea.

Following patrol of the Taiwan straits, combined fleet maneuvers with SEATO nations, and goodwill visits to ports of the Philippines and Japan, she returned to Long Beach 24 August 1957 for inactivation.