Canada's decision to bowl first backfired as last edition's finalists South Africa stormed to 4-213, despite Ansh Patel's three-wicket haul. In response, Canada could only get to 8-156, despite Navneet Dhaliwal's fighting knock of 64.
Markram (59 off 32 balls) started to fire early, putting together a 70-run partnership with Quinton de Kock within seven overs. The skipper completed his half-century in 28 balls, before falling to Patel (3-31).
An unbeaten 75-run partnership between David Miller (39) and Tristan Stubbs (34) put South Africa past the 200-run mark, as the two added 47 runs in the final three overs.
Player of the match Ngidi dismissed Canada captain Dilpreet Bajwa for a golden duck and also sent back Yuvraj Samra (12) and Nicholas Kirton (4) early. Kagiso Rabada then dislodged Shreyas Movva's (9) off-stump, leaving Canada reeling at 4-45 in the sixth over.
But Dhaliwal and Harsh Thaker (33) tried to keep Canada in the game with a 69-run partnership for the fifth wicket, until Ngidi got Thaker caught behind point.
By the time Marco Jansen (2-30) dismissed Saad Bin Zafar and Jaskaran Singh on back-to-back deliveries in the 18th over, it was already too late for Canada.
"We've seen at the start, anyone can beat anyone. You don't take anyone lightly," said Markram, with South Africa set to face last edition's semi-finalists Afghanistan in their next game on Wednesday.
