Dale Steyn and Johan Botha claimed three wickets apiece as South Africa stormed to a 128-run victory over Bangladesh to claim an unassailable 2-0 lead in the three-match one-day international series.

Hashim Amla clobbered a maiden ODI century as the Proteas, after being put into bat by the hosts, registered an intimidating score of 358 for four from their 50 overs.

Junaid Siddique and opener Tamim Iqbal were the only Bangladesh top-order batsmen to offer any resistance with knocks of 47 and 41 respectively.

Mashrafe Mortaza added a quickfire 34 from 22 balls towards the end of the innings but it was not enough to prevent the home team slumping to 230 all out from 49.2 overs.

The Bangladesh response had started promisingly with Tamim's 41 coming off just 22 deliveries before he became Steyn's first victim with the last ball of the fifth over, caught at square leg by Jean-Paul Duminy.

His fellow opener Imrul Kayes was next to head back to the pavilion, bowled between bat and pad by Botha for 14.

Captain Mohammad Ashraful contributed just five to the cause before being caught and bowled by Botha and Raqibul Hasan was then run out by Morne Morkel to leave Bangladesh on 127 for four in the 27th over.

Siddique's innings came to an end shortly after that when he was trapped lbw playing forward to become Botha's third scalp.

Three wickets then fell in quick succession as any hopes Bangladesh had of getting back into the match disappeared.

Shakib Al Hasan was bowled off an inside edge by Steyn for 17, Naeem Islam was caught by Kallis at slip also off Steyn for 16 and Mushfiqur Rahim found Albie Morkel at third man off the bowling of Morne Morkel for two as the hosts stuttered from 169 for five to 172 for eight.

Mashrafe stuck around for a little while for his 34 before Johann Louw had him caught at mid-off by Graeme Smith, and when Albie Morkel had Syed Rasel snapped up behind the stumps by Mark Boucher for one it was all over.

Abdur Razzak was left unbeaten on 20.

Earlier, Amla cracked 140 before he was caught at mid-wicket by Syed Rasel off the bowling of Mashrafe.

He shared an opening-wicket stand of 136 with Smith (65) before AB de Villiers (57 not out) and Albie Morkel (37no) took the Bangladesh attack to the cleaners late in the innings.

Jacques Kallis also chipped in with 49.

The fact Mashrafe was the pick of the bowlers with figures of one for 54 gives an indication of the punishment they took.

After being put in to bat, Amla and Smith set about making the tourists regret that decision as the runs flowed.

Smith was the first to go when he was caught in the covers by Ashraful off Islam.

But Amla and Kallis added another century stand before the all-rounder was bowled by Razzak.

The dismissals of Amla and Boucher, who made just six before being sent packing by Rasel, offered little respite to Bangladesh as De Villiers and Albie Morkel bludgeoned seven sixes between them to put South Africa in a commanding position.

The third and final match of the series takes place at East London on Wednesday before the first of two Tests gets under way in Bloemfontein on November 19.