Johannesburg - Bloemfontein Celtic and log-leaders Mamelodi Sundowns played to a goalless draw in their Premiership encounter at Botshabelo Stadium on Wednesday evening.
The Brazilians are unbeaten in nine consecutive league matches, winning four and drawing five.
The Tshwane giants top the table with 42 points with eight games remaining.
The first stanza started on an upbeat tempo with the visitors exerting pressure on the home side searching for an early lead.
Anthony Laffor and Nyasha Mushweki bothered Siwelele's defence but defender Mathoho Mulawandou stood head and shoulders above the rest and saved an early goal.
In the 31st minute Mushweki took a thunderous shot but struck the side netting.
Five minutes later Celtic's midfielder Cecil Oerson made a cross which striker Luyanda Bacela headed over the post.
In a threatening attack by the home team, Phenyo Mongala took a shot but it was well saved by Brazilian goalkeeper Calvin Marlin.
As the teams went into the break Sundowns enjoyed most of the possession and launched a number of attacks.
In the second half Celtic were the first team to make a serious attempt for the lead but Jackie Motshegwa's powerful shot went wide.
In the 70th minute substitute Lebohang Mokoena had a free header inside the box which was easily dealt with by Celtic keeper Thabani Stemmer.
In the dying minutes of the game the ball was swaying from one end to the other with both sides squandering scoring opportunities.