Had it not been for the expulsion of AS Vita from the CAF Champions League for fielding an ineligible player, Mamelodi Sundowns would have been watching the action from the sidelines. Thanks to the Congolese club's indiscretions, Sundowns are not only back in the big league but they are also in the driver's seat and on the verge of qualifying for the semifinals after beating Nigeria's Enyimba 2-1 in Pretoria last night.Leonardo Castro gave Sundowns the lead with a close-range strike in the 43rd minute. Ojo Oluwadamilare equalised for Enyimba in the 58th minute only for Wayne Arendse to score what was to be a crucial winner 19 minutes later.After ES Setif's expulsion - as a result of fan violence following their 2-0 defeat at the hands of Sundowns - GroupB has been reduced to three teams.This could work to the Pretoria team's advantage in their attempt to reach the semifinals, despite the disappointment of having their opening three points nullified.The Brazilians have put Enyimba - who lost their opening game 1-0 to Zamalek in Nigeria - on the back foot in a big way.They and Zamalek now each have three points. Enyimba have to come back from two defeats if they are to stand a chance of becoming one of the top two teams in the group to qualify for the semis.Sundowns were impressive, lifting themselves against their characteristically organised and robust Nigerian opponents.For a long period in the first half Enyimba stifled the Brazilians' creativity in midfield.But Sundowns stepped up to the plate for the opener. They got one when Keagen Dolly was played into space to square inside. Enyimba tried to scramble clear but the ball fell to Castro to sweep in from 7m.Enyimba brought the Champions League's top scorer Mfon Udoh on for playmaker Bartholomew Ibenegbu in the 53rd.Sundowns appeared to be gasping for air and allowed themselves to defend deep.From a corner they could not clear, allowing Oluwadamilare to rifle a right-footed shot into the top-right corner.Sundowns found their feet again and pressed forward.Asavela Mbekile made ground on the right and swerved in a fine cross that Castro deflected to force a save from goalkeeper Moses Ocheje.Later, during a goalmouth scramble from a corner, Arendse spooned in a volley at the far post...