NAGPUR, India (AP) — Former champions West Indies remained unbeaten and advanced to the World Twenty20 semi-finals earlier today after edging out South Africa by three wickets for their third straight win in Group 1. Marlon Samuels hit 43 off 44 balls and led West Indies to 123-7 in 19.4 overs after South Africa’s batsmen struggled on a slow wicket and limped to 122-8 with Quinton de Kock scoring a fighting 47 off 46 balls. The third successive chase after winning the toss earned West Indies six points and the 2012 champions can sweep the group by defeating Afghanistan on Sunday. South Africa will be eliminated if England, who already have four points, beat defending champions Sri Lanka tomorrow. South Africa have two points from their solitary win against Afghanistan, with a match against Sri Lanka to come. NOTE: Earlier this story had said the West Indies made 126 for 7 in 19.4 overs. That was incorrect. It was actually 123 for 7 in 19.4 overs since the batsmen completed the winning run before the ball hit the boundary. As dictated by the cricket rules, the boundary would not have been counted since the winning run was completed before the ball reached the ropes.