Geelong captain Joel Selwood's challenge of his striking ban was successful after the tribunal found him not guilty.
Just seconds after Thomas bumped Selwood's brother Scott, Joel came in to remonstrate with Thomas, and was charged with intentional conduct with low impact to the head.
Selwood was able to overturn the originally proposed one-game suspenion and is now cleared to play in Saturday's crunch game at GMHBA Stadium against the Swans.
Sydney will be without Lance Franklin and Dan Hannebery, after coach John Longmire ruled the pair out on Tuesday afternoon.