(CNN) -- South Africa crushed Ireland by 131 runs, securing their place in the last eight of the Cricket World Cup.
After a slow start, South Africa went on to build a respectable score of 272-7 in the Indian city of Kolkata, thanks in large part to a Man-of-the-Match innings of 99 by JP Duminy
Ireland, who produced arguably the only genuine shock of the tournament by beating England earlier in the group phase, had started strongly, taking an early wicket and restricting the Springboks to 117-5 .
But Duminy's sixth-wicket stand of 87 with Colin Ingram, plus a further 65-run partnership with Johan Botha for the seventh wicket, saw the Springboks take control.
Duminy went agonizingly close to recording a century, but was caught by Kevin O'Brien in the final over of the innings one run short.
In reply, Ireland was bowled out for 141, and eliminated from the competition in the process.
"We wanted to qualify. We've got one round robin game left against Bangladesh and hopefully three good games in the knockout phase. We've done the first part of it now," Graeme Smith, South Africa's captain, told AFP.
Although South Africa has now qualified from Group B, their final match against co-hosts Bangladesh still has huge significance.
Four teams -- India, West Indies, England and Bangladesh -- are now vying to fill the final three quarterfinal places.
With India all but guaranteed a place, England face the West Indies in a crunch, must-win match in Chennai on Thursday missing two of their best players.
Captain Andrew Strauss and spin bowler Graeme Swann have both succumbed to a stomach bug, and have been rated as doubtful for the clash.