The win moved Siwelele up to 10th spot on the league standings - three behind eighth placed Galaxy - and seven points clear of the relegation zone.
Bloemfontein Celtic ended a five-game winless run in the 2020-21 DStv Premiership season with a 2-1 victory over TS Galaxy at Dr Molemela Stadium on Sunday.
Celtic opened the scoring in the 13th minute through Menzi Masuku. The hosts were awarded a penalty after Given Msimango was adjudged to have brought down the forward inside the area, although replays suggested that there was no contact between the two players.
Nevertheless, Masuku dusted himself off before beating Marlon Heugh from the spot.
Galaxy pulled level before the break as Mlungisi Mbunjana netted a rare goal. The hard-running midfielder latched onto a pass from Mxolisi Macuphu before splitting the Celtic defence and firing home a rasping shot past Jackson Mabokgwane in the Phunya Sele Sele goal.
Victor Letsoalo restored Celtic's lead four minutes after the interval with his seventh goal of the league season. Masuku burst in behind the Rockets defensive line before teeing up the in-form forward who curled the ball past Heugh from the edge of the area.
In the end, Celtic did enough to earn all three points on the day.
Meanwhile AmaZulu FC secured a narrow 1-0 victory over Black Leopards in a 2020-21 DStv Premiership match at Thohoyandou Stadium on Sunday afternoon.
Victory moved Usuthu up to third on the league standings - level on points with second-placed Golden Arrows, while Lidoda Duvha remain in bottom spot, four points from safety.