Steve Bruce had the last laugh in the Carabao Cup at Newport – both in a penalty shoot-out and watching his players take cold showers at Rodney Parade.
Newcastle came within three minutes of exiting the competition after Tristan Abrahams' fifth-minute strike.
But Jonjo Shelvey struck a brilliant equaliser three minutes from full-time and Newcastle then triumphed 5-4 on penalties after Joelinton's miss had looked like costing them dear.
"They defended with their lives at the end and it took a real bit of quality because, the way it was going, I didn't think we would get the breakthrough," Bruce said.
"But I thought we played well in the last half an hour and we're through.
"I don't know if the lads enjoyed their cold showers at the end because there was no hot water.
"It's not something they're used to and it was quite amusing."
Newcastle pressed for long periods in the second half and, having started with Andy Carroll and Miguel Almiron in attack, sent on Callum Wilson and Joelinton to rescue the situation.
Time was running out when Shelvey delivered only his second goal of 2020 in stunning fashion from 20 yards.
Shelvey, Wilson, Fabian Schar, Jacob Murphy and Sean Longstaff converted from the spot as Ryan Taylor and Brandon Cooper missed for Newport.
"You can see how they've beaten Swansea and Watford. They play a certain way for a lower-division team," Bruce said.
"They get the goal early and, as if they didn't have enough belief, that gave them a bit more. We found it difficult and they defended with their lives.
"I think we had 27 attempts and we know not taking our chances is our Achilles heel."
Bruce confirmed that midfielder Dan Barlaser is in talks to join Rotherham.
The 23-year-old midfielder spent last season on loan at the Sky Bet Championship club, where he made 35 appearances.
Newport had beaten Leeds, Leicester and Middlesbrough in cup games in recent seasons, as well as holding Tottenham to a draw at Rodney Parade.
It was another heroic effort from the Sky Bet League Two side and manager Michael Flynn absolved Cooper of blame after the on-loan Swansea youngster had blazed over the decisive spot-kick.
"I'll not blame anyone for taking a penalty unless they try something stupid," Flynn said. "He had the character to take one and I couldn't be prouder if I tried.
"We were excellent and we have a fantastic group and it has taken a moment of magic to deny us.
"I know they had chances, but I thought we were brilliant and defended superbly. The Newcastle players were very complimentary to the boys at the end."
