South Africa thrashed Bangladesh by an innings and 273 runs to secure their biggest win and a 2-0 series sweep after enforcing the follow on and dismissing the hosts for 143 on day three of the second test in Chittagong on Thursday.Seamer Kagiso Rabada decimated Bangladesh with five wickets as the Proteas skittled the hosts for 159 in their first innings to take a huge 416-run lead and they turned up the heat further after asking them to bat again.Bangladesh, who lost the opening game by seven wickets in Dhaka, suffered a familiar collapse and were bowled out in the evening session as Keshav Maharaj claimed 5-59 and fellow spinner Senuran Muthusamy took 4-45.Sixteen Bangladesh wickets fell on the day at the Zahur Ahmed Chowdhury Stadium.South Africa's stand-in captain Aiden Markram said he was incredibly proud of the team after they eclipsed their innings and 254-run win over Bangladesh in Bloemfontein in 2017."Hard work went into it and it's nice to see the hard work pay off," Markram said."We played really good cricket in both tests especially considering they were in conditions we're not used to."Rabada dismissed Najmul Hossain Shanto for nine, Mehidy Hasan Miraz for one and Mahidul Islam Ankon for a duck to finish with 5-37 while Dane Paterson got rid of Mushfiqur Rahim for nought as Bangladesh continued to wobble in the first innings.The hosts, who resumed the day on 38-4, staged a fightback from 48-8 with Mominul Haque making 82 but his dismissal shortly after lunch by Muthusamy ended his 103-run ninth-wicket stand with Taijul Islam.Taijul was unable to frustrate the tourists further, as he became Maharaj's second victim after a defiant 30.South Africa were even more ruthless in the second innings to seal a