The gunman who allegedly killed 50 people at two mosques in New Zealand was on his way to commit a third massacre when he was stopped by cops, authorities said.

New Zealand Police Commissioner Mike Bush told reporters Wednesday local time that the lone gunman was on his way to slaughter more people when the officers —who were in the middle of a training session on how to handle gunmen — tracked him down and dragged him out of his car.

“Lives were saved,” Bush said, according to Buzzfeed News.

The officers, who were not named, booked it from a training session on handling armed offenders when they got the call about an active shooter in Christchurch, The New Zealand Herald reported.

Cops nabbed the suspect, 28-year-old Brenton Tarrant, 21 minutes after the call.

The white supremacist shooter was speeding and weaving in and out of traffic, when the officers rammed into him, and pulled him out of the driver’s side onto the sidewalk, according to the Herald.

“They were trying to catch up with him, they were discussing tactics – did they want to pursue him?” said the officers’ manager, Senior Sergeant Pete Stills.

“They decided to bring it to an end as quickly as possible and they decided to immobilize the car by ramming it.”

Authorities have said that IEDs and other weapons were found in the suspect’s car — which the officers, who have 40 years of experience between the two of them, made sure to warn their colleagues about.

The gunman didn’t give himself up easily and was “non compliant,” Bush said. Still, the officers remained cool under pressure.

“I was surprised how calm and collected they were,” Stills said.

“It was a good catch,” he added. “You could police for 100 years and not get an apprehension anywhere near that good.”

After the arrest, “one of [the officers] phoned me straight after to advise me that they’d damaged a car,” Stills said.