Sydney has struggled for momentum since being crowned premier for a record fourth time on 25 July and was behind early on in Monday's clash at McDonald Jones Stadium.
Dylan Wenzel-Halls latched on to Jay O'Shea's throughball - possibly intended for Scott McDonald - and coolly lifted over Andrew Redmayne with 11 minutes on the clock.
However, three minutes after hitting the post, young winger Ivanovic got off the mark for the season with an impressive curled finish into the top-right corner.
The visitor came closest to winning the game in a goalless second half, Jamie Young producing a number of good saves, including a triple stop 17 minutes from the end.
Sydney could not find a way through and is now on its longest streak without a win since April 2016, while the Roar are unbeaten in three heading into the Elimination Final.