Green was ejected after getting two technical fouls in the second quarter of the 116-86 setback Thursday at Chase Center in San Francisco.
Green will get a one-game ban if he gets two more technical fouls.
The Warriors star had two points, two fouls and a rebound and the game was tied at 24-24 entering the second quarter. He picked up his first technical 5:56 before halftime. Lakers guard Kyle Kuzma had the ball at the top of the 3-point arc while Green was defending Lakers center Dwight Howard in the paint. Howard got leverage on Green, pushing him away from the basket so he could get a pass from Kuzma. Green then fell to the ground, taking Howard down with him as he hit the floor.
Green was given a personal foul before complaining to a referee. He was given a technical for his post-play tirade. He drew his second technical foul about 11 seconds later.
Kuzma was dribbling in the corner during the second sequence, while Green was trying to defend the Lakers guard. Howard set a screen on Green, who again fell to the ground. Green stuck his foot out while on the ground and a referee determined he was attempting to trip Howard. Green was given another personal foul before drawing a technical for again yelling at the officials.
Green had two points, four assists, three turnovers and a rebound in nine minutes before his exit.
"We needed him in the second half," Warriors coach Steve Kerr said of Green. "We really missed him."
Green, Westbrook and Kevin Durant led the NBA with 16 technical fouls apiece last season. Green finished second in technical fouls in 2017-2018.
Anthony Davis led the Lakers with 23 points and six rebounds in the win. Kuzma scored 18 points off the bench for the Lakers. Howard had 13 points and nine rebounds off the bench. Eric Paschall scored 23 points for the Warriors. LeBron James did not play in Thursday's game.
Green is averaging 8.0 points, 6.2 assists and 6.2 rebounds per game this season. The Warriors (12-47) face the Phoenix Suns at 9 p.m. EST Saturday at Talking Stick Resort Arena in Phoenix. The Lakers (45-12) face the Memphis Grizzlies at 8 p.m. Saturday at FedExForum in Memphis.