Abdul Aziz was in the Linwood mosque when the shooter opened fire during Friday prayers, killing dozens.
Mr Aziz picked up the first thing he could find - a credit card machine - and ran outside screaming "Come here!''
Mr Aziz (48) has been praised for saving many people inside by leading the gunman on a cat-and-mouse chase before scaring him into speeding away in his car.
But Mr Aziz, whose four sons and dozens of others remained in the mosque while he faced off with the gunman, said he thinks it is what anyone would have done.
The accused gunman Australian Brenton Tarrant (28) killed 50 people in terror attacks at two mosques in the deadliest mass shooting in New Zealand's history.
Tarrant has been charged with one count of murder over the slayings and a judge said on Saturday that it was reasonable to assume more charges would follow.
Latef Alabi, the Linwood mosque's acting imam, said the death toll would have been far higher at the Linwood mosque if it was not for Mr Aziz.
Mr Alabi said he heard a voice outside the mosque about 1.55pm and stopped the prayer he was leading and looked out of the window.
He saw a man wearing black military-style gear and a helmet holding a large gun, and assumed it was a police officer. Then he saw two bodies and heard the gunman yelling obscenities.
"I realised this is something else. This is a killer,'' he said.
He yelled at the congregation of more than 80 to get down. They hesitated. A shot rang out, a window shattered and a body fell.
"Then this brother came over. He went after him, and he managed to overpower him, and that's how we were saved,'' Mr Alabi said, referring to Mr Aziz.
"Otherwise, if he managed to come into the mosque, then we would all probably be gone.''
He said he could hear his two youngest sons, aged 11 and 5, urging him to come back inside.
The gunman returned and fired. Mr Aziz said he ran, weaving through cars parked in the driveway, which prevented the gunman from getting a clean shot.
Then Mr Aziz spotted a gun that had been discarded by the attacker and picked it up, pointed it and squeezed the trigger. It was empty.
He said the gunman ran back to the car for a second time, probably to grab yet another weapon.
"He gets into his car and I just got the gun and threw it on his window like an arrow and blasted his window,'' he said.
The windshield shattered, Mr Aziz said. "That's why he got scared.''
He said the gunman was cursing at him and yelled that he was going to kill them all. But he drove away and Mr Aziz said he chased the car down the street to a red light, before it made a U-turn and sped away.
Online videos indicate police officers forced the car from the road and dragged out the suspect soon after.
"I've been to a lot of countries and this is one of the beautiful ones,'' he said. And, he always thought, a peaceful one, as well.
Mr Aziz said he did not feel fear or much of anything when facing the gunman - it was like he was on autopilot. And he believes that God, that Allah, did not think it was his time to die.
A man who was at the Linwood mosque on Friday said he felt nothing during the massacre aside from a certainty he was about to die.
Mohammed, who would only give the Otago Daily Times his first name, said he was at prayer when he heard what he thought were fireworks outside the mosque.
But it was compulsory not to move during prayer and they carried on.
"We were praying, then we heard gunshots, I thought somebody was using firecrackers.''
"We didn't recognise something was happening.''
The bangs become louder and louder as the gunman moved closer, before a second Imam started another prayer to the effect of "God save us, if something's happening,'' Mohammed said.
"Then, suddenly, we saw the man come inside. He just start shooting from the back; we were praying in front.''
The shooting stopped for a while as people lay dead around Mohammed, before starting again.
"There's nowhere to hide in that place, and there was no exit.
"The only entry was where he was standing.
"If the shooter came inside there would have been heaps of dead.''
But this did not come to pass, thanks to the valiant efforts of Mr Aziz at the mosque.
