Cape Town - Mamelodi Sundowns booked their place in the Nedbank Cup last-16 as they laboured to a 2-0 win over Mariveni United at the Lucas Moripe Stadium on Monday.
Sundowns dominated proceedings from the get-go but they struggled to break down the visitors, who were defending in numbers.
Tapfumaneyi Dodo's men had the first chance of the game in the fifth minute, although Tshepo Rakgoale failed to hit the target with a long-range free-kick that he dragged well wide of the left post.
The Brazilians finally found an opening when Anthony Laffor was played into the area on the right in the 12th minute, but Hlulani Mbhumbhi parried his shot behind, and the Liberian wasted a glorious opportunity 10 minutes later as he fired over from just eight yards in an unmarked position following a cross on the left.
Castro then almost capitalised on a mistake from Mbhumbhi, who spilled the ball after Wayne Arendse headed a cross back towards goal from the left, but the Colombian striker could only hit the side-netting from an acute angle in the 37th minute.
Downs continued to probe and Thabo Nthethe headed over from a cross on 39 minutes before Teko Modise sent a shot just wide of the left post from 22 yards out in stoppage time.
Mbhumbhi kept AmaNandos in the cup-tie with a brilliant save to deny Castro from six yards out on 49 minutes following Thapelo Morena's cross on the right, but there was a collective sigh of relief around the stadium when the South American headed home a cross from Fares Hachi moments later.
Motjeka Madisha went close with a shot that was deflected narrowly wide of the right post by Laffor, who then nodded in the second from close range on 52 minutes after Castro's initial header had bounced back off the crossbar.
Masandawana had the ball in the back of the net again on 63 minutes when Vilakazi steered in Morena's header back across goal from a free-kick on the left, but it was disallowed for a foul on Mbhumbhi by Castro.
The hosts threatened again through Castro, who directed his header straight at Mbhumbhi from Hachi's cross on the left in the 70th minute, before Mzikayise Mashaba fired inches wide of the right post with an angled shot five minutes later.
Sundowns went in search of more goals in the closing stages but the closest they came was when Arendse let fly from outside the area on the left in the 88th minute, with Mbhumbhi gathering his shot at the second attempt.