At 1000 hours, the masts of a vessel were observed on the horizon. Cappellini took an intercepting course.

At 1045 hours, at a distance of 3,000 metres, the merchant ship opened fire. Cappellini altered course to starboard and opened fire with her artillery. The enemy's gunfire was accurate and, at 1100 hours, a shell exploded close to the submarine's aft gun and mortally wounded the gunner Giuseppe Bastoni who fell overboard. He was posthumously awarded the Medaglia d'Argento al Valore Militare. But the freighter was now being repeatedly hit by the submarine's artillery. At 1127 hours, the white flag was run up the mast and she sank. This was the British Shakespear (5,029 GRT, built 1926), carrying 8,000 tons of coal from Milford Haven to Alexandria via Capetown, a straggler from convoy OB.262.

The submarine turned back and conducted a thorough search to locate Bastoni, but he was never found.

C.C. Salvatore Todaro, who was to earn the nickname of the "Knight of the Atlantic", was a chivalrous man. He returned to the site of his sinking and rescued twenty-two survivors (including eight wounded, one of whom would die shortly after) and landed them on the Island of Sal (Cape Verde).

The destroyer HMS Velox arrived on the scene but found only wreckage. The Portuguese destroyer Gonçalves Zarco found twenty-five survivors (including ten wounded) and landed them on São Vicente Island (Cape Verde) on 9 January 1941.