Quinton de Kock and Hashim Amla served up the third highest opening partnership in one-day internationals to take South Africa to 282-0 and a 10-wicket win over Bangladesh overnight.
De Kock finished 168 not out off 145 balls and ended the game with back-to-back fours as South Africa romped to a 1-0 lead in the three-match series. Amla played a more measured innings to be 110 not out from 112 deliveries.
Their 282-run stand was a South African record for the first wicket and only four runs short of the world record for an opening stand, set by Sri Lanka's Upul Tharanga and Sanath Jayasuriya in 2006.
South Africa didn't need to call on AB de Villiers to show his form with the bat after he was recalled following a sabbatical.
Bangladesh made 278-7 batting first thanks largely to 110 not out by Mushfiqur Rahim, but that total always looked a little light on a true pitch at the Diamond Oval in Kimberley.
Kagiso Rabada took 4-43 to be South Africa's most effective bowler.