The fight happened right after Red Wings defenseman Simon Edvinsson got tangled up with Senators forward Tim Stutzle near the end of the first period.
Tkachuk and Edvinsson fought at the center of the ice, throwing punches until the referees stopped them. This was Tkachuk's second big fight this month.
Brady's dad, Keith Tkachuk, a former NHL star, was in the crowd at Little Caesars Arena and was pumped up watching his son fight.
He cheered as Brady's actions fired up the Senators, who were already winning 2-0 by the end of the first period.
Sens helped by refs in win against Red Wings
Sadly for the Red Wings, they were once again dealt a rough hand in poor officiating, with several missed calls, including this one on Lucas Raymond which would ultimately lead to a Senators goal:
No call on Tkachuk taking down Raymond and Ottawa turns around and scores. #LGRW
The Senators ended up beating Detroit 4-3, though the Red Wings made it close by scoring two goals late in the game, getting within one goal with less than five minutes left.
Thomas Chabot scored first for Ottawa, followed by goals from Stutzle and David Perron to make it 3-0. Michael Amadio added the last goal for the Senators, and Red Wings' playoff hopes got lower and lower.