Bobo headed in a cross from Luke Brattan after six minutes as Sydney ended a run of three consecutive draws to move one point behind leader Melbourne City, though the Sky Blues have played two games more.
Victory remains second-bottom despite a battling performance without suspended quartet Callum McManaman, Robbie Kruse, Jake Brimmer and Adama Traore.
Sydney forward Kosta Barbarouses had three efforts kept out by Matt Acton, who ended the match with an impressive nine saves that kept the contest close.
The host side was worthy winners, finishing with 10 shots on target to Victory's three, Alex Baumjohann creating five chances in a lively showing.
Ben Folami squandered a headed opportunity for Victory while Lleyton Brooks hit the post in the second half with an aerial effort of his own as Sydney almost paid the price for not putting the result beyond doubt.