The 21-year-old sealed a 2-0 victory deep into injury time with his first goal of the season as the Magpies finally cleared a tricky hurdle.
Pardew has known for some time just how talented the younger Ameobi is, but it has taken him time to adapt to the demands of senior football.
However, he believes the penny has finally dropped.
The manager said: "Sammy put in a really good display offensively and defensively. We have had problems with him defensively in the past.
"We have never doubted his talent, but he put it all together this pre-season and that was shown tonight.
"I thought he was the difference between the two teams until Hatem [Ben Arfa] came on, who then really did open the game up for us."
Sammy Ameobi started the game and was one of the few positives for Newcastle during a first half which proved more than uncomfortable.
Had it not been for midfielder Dan Gosling's attention to detail, both Mark Hughes and Padraig Amond might have headed the League Two side into the lead inside the opening 21 minutes.
Amond also forced goalkeeper Rob Elliot into two important saves in a first half which gave Jim Bentley's men every encouragement.
Pardew, who is desperately hoping director of football Joe Kinnear can land his transfer targets during the remaining days of the summer window, made his move at the break when he replaced Haris Vuckic with the more physical Shola Ameobi, and saw the newcomer pass up a glorious 49th-minute opportunity to score.
But when his second chance arrived with six minutes remaining, he made no mistake, spinning on Ben Arfa's pass and firing home from 20 yards with the help of a deflection off the unfortunate Hughes.
His younger brother's big moment arrived deep in stoppage, time with Ben Arfa again the supplier as the Magpies booked a home third-round tie against Leeds.
Pardew said: "It was a good cup-tie, wasn't it? When you get a Premier League side coming down, that's the sort of response you want from a home team.
"A League Two team is going to show you what it's about. They are proper professionals, proper people who play the game for their livelihoods to pay their mortgages.
"We had to stand up to that and I am very pleased with the young players I put in."
Bentley was delighted with the way his players handled the challenge and very nearly bloodied the nose of a top-flight club.
He said: "It's a good competition and I think we showed tonight - and Newcastle showed, to be fair, it was a proper cup tie.
"It wasn't just a case of they turned up, we had a little game of football, we shook hands and we went home. You could see both sets of players wanted to win the game."