Roger Mukasa looked solid at the other end helping his side move past 50 in the seventh over, before losing another partner, Nandi Kishore bowled by Blain.
BBC: Uganda sunk by McCallum century
2.
But Mukasa perished in the next over when he was bowled by Nel for an aggressive 37 in 32 balls as the Africans slumped to 56 for four.
BBC: Uganda sunk by McCallum century
3.
Smith was next to go, stumped by Mukasa, the bowler being Nsubuga, which was followed by the wicket of Poonia - run out for one by Kwebiha while trying to scamper a second run.