Sydney FC has dominated the A-League this season and is eight points clear of second-placed Melbourne City with two games in hand.
However, its only two defeats of the campaign came courtesy of 1-0 reverses against the Wanderers, who hosted the game behind-closed-doors on Saturday.
Adam Le Fondre applauded and bowed to the deserted stands when he put the Sky Blues in front after 35 minutes, reacting quickest when Daniel Lopar parried Kosta Barbarouses's effort to net a 17th goal this term.
But Western Sydney responded impressively, dominating the second half and earning the fortune that came its way eight minutes from time.
Yeboah did not appear to know much about Simon Cox's shot when the ball struck him and spun beyond a helpless Andrew Redmayne in the Sydney goal.
The Wanderers lie eighth and retain post-season ambitions as they sit a point behind sixth-place Western United, having played a game more.