Haughey, who entered her heat off the back of a successful title defence in the women’s 200m freestyle on Monday, touched the wall first with a convincing time of 53.60 seconds.
She finished 0.62 seconds ahead of Philippine swimmer Kayla Sanchez, with Li coming third in a time of 55.58 seconds.
Only the top eight swimmers from the heats advance to the final.
The SAR swimmers are due to compete in the final on Tuesday afternoon.







