Sikhakhane was shown the door after a run of four successive league defeats left the Chili Boys second from bottom on the Premiership table.
He initially helped steer United to top-flight promotion, before he was forced to vacate the position for medical reasons.
Goalkeeping coach Farouk Abrahams has since been appointed as caretaker at the Philippi-based outfit.
Sikhakhane only regained the reins last month from caretaker boss Julius Dube, who succeeded the sacked Manqoba Mngqithi in August.
Having lasted just two matches in charge of Chippa, new Golden Arrows coach Mngqithi ironically guided Abafana Bes'thende to a 2-0 win on Saturday over his former club.