The Cheetahs and Southern Kings will face a tough test in the PRO14 this weekend as they line up against the only unbeaten teams in the competition in the fourth round.
The Free Staters will kick off the weekend's action on Friday evening against Ulster in Bloemfontein, while the men from the Eastern Cape take on the Glasgow Warriors in Port Elizabeth on Saturday.
At Free State Stadium, the Cheetahs will be hunting their first victory of the season against the Irishmen, who will be looking to stretch their winning run in the competition to four matches and maintain their unbeaten status against South African sides.
The teams have only met once before in Belfast, where Ulster registered a convincing 42-19 victory. They have been closely matched on attack this season, with both sides boasting six tries in the first three rounds, which should boost the Cheetahs' confidence.
However, good discipline will be vital for Franco Smith's men, as Ulster have kicked 11 penalty goals so far in the competition - all by John Cooney, the top try-scorer in the series - while they also need to tighten up their defence after conceding 52 points last week.
They will also have to contain Springbok loose forward Marcell Coetzee, who has been a stand-out performer on attack and defence, with 22 carries last week alone, while he was also a handful at the breakdowns.
The Southern Kings will also have their work cut out against the Glasgow Warriors at the Nelson Mandela University, as the Scottish visitors will be high on confidence after three victories in a row - two of which were on the road - and with two bonus points for tries.
The Port Elizabeth outfit went down 43-13 in the only other match between the sides in Glasgow, but with coach Deon Davids' men showing promise on attack this season, they are expected to challenge the visitors.
The Southern Kings, however, will have to be rock-solid on defence as the Glasgow Warriors are the joint top try-scorers in the competition with 14 tries, while they will also need to improve their finishing after missed opportunities cost them two possible victories in the last three weeks. PRO14 Round 4 fixtures: Cheetahs v Ulster
Date: Friday, September 21SA time: 19:15Venue: Fee State Stadium, BloemfonteinReferee: Ben Whitehouse (WRU)Assistant referees: Sam Grove-White (SRU) and Ben Crouse (SARU)TMO: Johan Greeff (SARU)TV: SS1 Southern Kings v Glasgow Warriors
Date: Saturday, September 22SA time: 15:00Venue: Nelson Mandela University Stadium, Port ElizabethReferee: Andrew Brace (IRFU)Assistant referees: Frank Murphy (IRFU) and Paul Mente (SARU)TMO: Marius Jonker (SARU)TV: SS1 Other Round 4 action (SA kick-off times):
Friday, September 21:
20:35 - Cardiff Blues v Munster, Cardiff Arms Park Saturday, September 22:
18:15 - Connacht v Scarlets - The Sportsground, Galway18:15 - Dragons v Zebre - Rodney Parade, Newport20:35 - Leinster v Edinburgh - RDS Arena, Dublin20:35 - Ospreys v Benetton - Liberty Stadium, Swansea