Wigan prop Ben Flower has been given a six-month ban - the longest in Super League history - for punching St Helens' Lance Hohaia.
Flower, 26, punched Hohaia to the ground two minutes into Saturday's Grand Final, then landed a second blow to his face while he lay on the ground.
Wales prop Flower was sent off as the Warriors were beaten 14-6.
The ban until 14 April takes in 10 Super League games and the World Club Series match against Brisbane Broncos.
New Zealander Hohaia had already accepted a one-game suspension for a forearm strike which came before Flower's punches.
|Analysis: BBC Radio 5 live's George Riley|
|"It's the worst thing I've seen on a league pitch and the ban had to be huge. Flower's horrible error of judgement has hurt the sport. It ensures this final will always be remembered for that disgusting mistake rather than as the year St Helens ended their losing run. But to suggest rugby league might be irreparably damaged by this is ludicrous. It has been dealt with correctly and one high-profile individual implosion should not tarnish rugby league's proud reputation as a family sport."|
Flower was charged with a Grade F offence - the most serious in the sport's disciplinary rules - of "violent and aggressive punching" and "punching an off-guard opponent", a charge which carries a minimum of an eight-game ban.
Wigan rugby general manager Kris Radlinski, who accompanied Flower to the hearing at the Rugby Football League in Leeds, said in a statement: "Wigan Warriors would like to go on record in saying that the RFL disciplinary committee handled a very difficult situation with professionalism and integrity.
"We fully support their assessment of Saturday night's incident involving our player, Ben Flower. We will be making no appeal.
"We would like to apologise to Lance Hohaia and his family and to the St Helens club and fans. St Helens' win on Saturday has been overshadowed by the incident and that is wrong."
In becoming the first man to be sent off in a Grand Final, Flower left his side down to 12 men for the vast majority of the match at Old Trafford, which St Helens won to end an eight-year wait for the Super League title.
|St Helens captain Paul Wellens on BBC Radio 5 live|
|"I'm not surprised. It's a given it was going to be a lengthy suspension. It was a pretty unsavoury incident. He's said himself he is very disappointed, but it's quite clear the RFL have sent a message that that type of behaviour won't be tolerated. "I've met Ben and he's a really nice lad and he's said it's really out of character for him and I'm sure he'll be hurting."Rugby league people in general are quite forgiving. There will be a lot of scrutiny when he returns but he will go away and serve his punishment and after that he will be integrated back into the Wigan team as normal."|
Saints chairman Eamonn McManus said: "The sport of rugby league should not be judged by this event, but by how it deals with it.
"We must assist [Flower] in any way that we can and accept him back into the sport. There is a person behind the player, and I am reliably informed by all that it is a good one."
For Wigan, the defeat ended their defence of the Super League crown and the pursuit of a fourth title.
Former Wigan and Great Britain player Martin Offiah told BBC Radio 5 live: "There is a lot of emotion around what was a big occasion but sadly it was in effect ruined by this incident in which I believe both players played their part. It was a sad day for rugby league.
"The sport was on show, it's a big event and the pictures are very graphic and all the apologies in the world won't wipe these away.
"No one can condone that second punch to the head and he's apologised for that but Lance Hohaia must take some consideration for his actions."
Meanwhile, Greater Manchester Police said in a tweet they are investigating "abusive social media activity" surrounding the Grand Final.