Geelong put their foot down again but only extended their lead by another 13 points as they stretched the margin to 27 points at halftime.
The Saints missed two set shots inside the final minute which would have brought them closer.
Jay Polkinghorne of the Cats celebrates kicking a goal.Getty Images
Jay Polkinghorne was excellent but missed goal scoring opportunities while James Worpel, Gryan Miers, Bailey Smith and Max Holmes were dangerous.
The Cats have not played four quarters for a while so the game is up for grabs.
The inclusions have been good but they need more from their three forwards Ollie Henry, Shannon Neale and Patrick Dangerfield who have six touches between them.
St Kilda have lacked output from their key forwards but the Cats have starved them leading the inside 50 count 31-20.