SINGAPORE, May 2 (Reuters) - DBS Group, Singapore's biggest bank, posted on Thursday a 15% rise in net profit in the first quarter to a record high of S$2.96 billion ($2.18 billion) from a year earlier, driven by strong total income growth. ($1 = 1.3600 Singapore dollars) (Reporting by Yantoultra Ngui Editing by Chris Reese)