The cruiser was one of the escorts for the Tiger Convoy between Malta and Alexandria in early May. When the Germans invaded Crete on 20 May, "Perth" was part of Force C that consisted of two cruisers and four destroyers, patrolling in the vicinity of the Kasos Strait, northeast of Crete. The following day they were repeatedly attacked by German and Italian aircraft that sank one of the destroyers. Now assigned to Force D, "Perth" and her consorts intercepted a German invasion convoy of small ships on the morning of the 22nd, escorted by the Italian torpedo boat . "Perth" sank a straggler from another convoy before the main convoy was spotted at 08:47. The torpedo boat had been trying to collect stragglers and her commander ordered his convoy to disperse while he laid a smokescreen and then engaged the Allied ships with little effect. His diversion and the lack of visibility caused by his smokescreen, coupled with repeated aerial attacks that peppered the ships with shrapnel, allowed the convoy to escape with only the loss of two ships. Upon her return to Alexandria, "Perth" spent a few days under repair.