Los Angeles - Baker Mayfield threw four touchdowns as the Cleveland Browns rolled over the Pittsburgh Steelers 21-7 on Thursday in a game that was marred by a helmet-swinging brawl in the closing moments.

Cleveland defensive end Myles Garrett is likely facing one of the longest suspensions in NFL history after ripping off the helmet of Mason Rudolph and clobbering the Pittsburgh quarterback with it with just eight seconds to go in the fourth quarter.

Garrett was one of three players ejected for the wild melee but faces the harshest penalty because he appeared to be the main instigator.

Rudolph described Garrett as a "coward" and said that his helmet swinging was "bush league".

"It is a total coward move on his part. I am not going to back down from any bully out there," Rudolph said after the game.

Garrett got tangled up with Rudolph after a play and pulled Rudolph's helmet off by the facemask. While being restrained by Steelers offensive linemen David DeCastro, Garrett then swung it wildly overtop and clobbered Rudolph on the head with it.

The play began with Garrett dragging Rudolph to the ground and then refusing to let go as the quarterback tried to break free.

Rudolph, who was concussed and knocked unconscious by a helmet-to-helmet hit earlier this year, eventually rose to his feet and chased after Garrett and that is when he was clobbered with his own helmet.

Seconds later another Browns' player, defensive tackle Larry Ogunjobi, rushed up to Rudolph and hit him from behind knocking him to the ground a second time.

Meanwhile, DeCastro tackled Garrett, and Steelers centre Maurkice Pouncey ran around the two and threw several punches at Garrett before trying without success to kick him in the head.

Referee Clete Blakeman ejected Garrett, Ogunjobi and Pouncey.

"I've never seen that in my life," Cleveland coach Freddie Kitchens said.

"I'm embarrassed, Myles is embarrassed. He understands what he did. He understands what he did is totally unacceptable."

Browns quarterback Mayfield, who helped engineer Cleveland's first win over the Steelers in more than five years, said teammate Garrett deserves to be suspended.

"I didn't see why it started, but it's inexcusable," Mayfield said. "I don't care, rivalry or not, we can't do that.

"That's just endangering the other team. That's inexcusable. (Garrett) knows that.

"The reality of it, he's going to get suspended, and that's going to hurt our team."

The Browns beat the rival Steelers for the first time since October 2014 after losing seven of the previous eight meetings.

'I lost my cool'

Garrett said it was not like him to lose his temper like that.

"I made a mistake, I lost my cool," Garrett said after the game.

"What I did was foolish, and I shouldn't have allowed myself to do stuff like that. It's out of character."

Rudolph said he wasn't hurt in the fiasco.

"I'm fine," Rudolph said.

"I'm good. Good to go."

Several current and former NFL players expressed outrage on social media with some calling for a season long suspension and others saying they had never seen anything like it.

wrote Kansas City quarterback Patrick Mahomes.

Said Marcus Gilbert of the Arizona Cardinals,

said Reggie Bush, a former Heisman Trophy winner who retired from the NFL two years ago.

he added.

The longest suspension for an on-field incident in league history is the five games that Albert Hanyesworth got in 2006 for stomping on another player's head.