Having beaten domestic opposition on South African soil in their opening two matches, the Sharks headed to New Zealand and notched three tries in their 22-15 triumph over the Chiefs in Hamilton.
Steyn grabbed the first to give the visitors a 7-3 interval lead before Pietersen ran on to two beautifully weighted kicks ahead from firstly his centre Steyn and then outside half Ruan Pienaar to edge the Sharks further ahead.
All three players will come into the reckoning to do similar damage to Ian McGeechan's British & Irish Lions side this summer and there is no doubt that the midfield combination of Pienaar and Steyn could be Springbok coach Peter de Villiers' first choice pick.
But while the Sharks were able to run in there tries they ended the game hanging on grimly as the Chiefs mounted a spirited fightback. In the end, the Television Match Official came to their aid as he twice ruled out potential Chiefs scores from skipper Liam messam and threequarter replacement Mike Delany in a frantic finish.