Wanklyn's first success in this theatre was an attack on a large ship escorted by a destroyer heading to port in Tripoli. At 01:30 on 26 January 1941 he began his attack surfaced. He evaded the destroyer but both torpedoes missed. Later another convoy was sighted and he fired two torpedoes but once again, both missed. On 28 January 1941 Wanklyn's lookouts sighted another convoy. Closing undetected to 900 yards, he scored one hit on the 7,500-ton transport "Duisburg", which was damaged. On 30 January 1941 he fired two torpedoes at a northbound convoy and claimed a hit on a 5,000-ton cargo ship which has not been confirmed. Having expended all of his torpedoes, "Upholder" berthed in Malta on 1 February. He was promoted lieutenant commander on 1 February 1941.