Pochettino's men produced an outstanding performance to cruise to a thoroughly deserved success over Alan Pardew's visitors.
And it was three of Southampton's England FIFA World Cup hopefuls that made the difference as Jay Rodriguez scored a brace while Rickie Lambert and Adam Lallana also found the net.
Rodriguez gave Southampton the lead when he finally beat Rob Elliot in injury time of a first half that had been defined by an array of outstanding saves from the Newcastle reserve goalkeeper.
That goal opened the floodgates, Lambert doubling the advantage in the 49th minute before a fine long-range Lallana effort and Rodriguez's late second completed a resounding triumph.
And Pochettino felt the final score was a perfect illustration of his side's dominance.
"We had an amazing performance today and not just the final result but the way that we played today was outstanding," Pochettino said.
"There have been games in the past where we played very well but the final result didn't show how well we played.
"Today that did not happen, I think overall we're still a developing team, we're a growing team.
"We're still improving and the result today is a very important result for our development as a team and I'm just very happy overall with the performance of the players today."
Pochettino also expressed his delight at the consistency of his attacking trio, which he feels is a positive for their chances of being selected for England's World Cup squad.
"It's clear that for the three England players that we have here at Southampton, it's very good to maintain those high standards that they're showing throughout the season," Pochettino added.
"That is only going to increase their chances of actually going to Brazil so it's very good for them. It's good for us as well."
