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 faces a lengthy suspension from the NFL after ripping off Mason Rudolph's helmet 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 fight but faces the harshest penalty because he appeared to be the main instigator.

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

"It is bush league. I will never back down," said Rudolph.

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 get 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.

Browns quarterback Mayfield 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 Steelers for the first time since October 2014 after losing seven of the previous eight meetings.