North Queensland secured the victory against Parramatta on the back of an unlikely Blake Ferguson error.
Ben Barba will be banned for life by the NRL if domestic violence allegations are proven.
The former Dally M winner was sacked by North Queensland on Friday after club officials viewed CCTV footage of an incident at a Townsville casino on the Australia Day weekend.
Barba is alleged to have assaulted his partner and mother of his four children, Ainslie Currie, and is being investigated by police.
NRL chief executive Todd Greenberg said the game would refuse to register any future contract if he was found guilty.
“We have run out of patience and tolerance for misbehaviour off the field,” Greenberg said on Saturday.
“Violence against women is the very top of that list. If you’re violent against a woman you can expect to be removed from the game. It starts now.
“The Cowboys have acted quickly and decisively to terminate Ben Barba’s contract. That’s a club showing the leadership that’s required.
“I haven’t seen the footage as yet but if it shows violence towards a woman then really there’s no debate. Ben Barba will be out of the NRL immediately and I can’t see him ever returning.”
The 29-year-old was already on his last chance after being forced out of the game in 2016 after recording his second illicit drugs strike following Cronulla’s premiership win.
He was forced over to French rugby union and the English Super League before being thrown a lifeline by the Cowboys.
Barba will depart the Townsville club without playing a game as the NRL’s horror off-season continued.
It’s yet another troubling look for the code, with Jarryd Hayne, Jack de Belin, Zane Musgrove, Liam Coleman, and Dylan Walker also facing charges of serious offences against women.
Should those players be found guilty, the precedent set by the NRL on Saturday will have ramifications for them.
Greenberg said the commission had drawn a line in the sand and was frustrated that previous sanctions had not affected player behaviour.
“It’s disgraceful and we can’t do anything other than protect the game,” Greenberg said.
“That’s what we will do. I called this out several weeks ago. I said that don’t look behind us and what sanctions have been applied, only look in front.
‘We’re going to get tougher, we’re going to get tougher and get tougher on this sort of stuff because we must protect the game. It’s exactly what we’re doing on the first opportunity to do so.”