Brown’s two goals were just reward for a player who has been quietly impressive for far longer than this campaign, and he was part of a back-five which stood out in what was a third consecutive clean sheet.
Brodie Spencer and Terry Devlin were drafted in at the full-back positions and both impressed, but Brown’s centre-back partners McConville and Tom Atcheson really shone.
Norwich City defender McConville, 21, commanded his area well and, as well as an assist for Brown, he also allowed the ball to trickle over the line when he could have touched home for the third goal instead of his team-mate.
Atcheson, himself only 20 and playing for Blackburn Rovers in the Championship, made his Northern Ireland debut in Wales in March, but showed composure beyond his years.
O’Neill said both players were “terrific” as he told BBC Sport: “They have no ceiling, to be honest.
“They are both playing in the Championship at the minute but they are ready to go to the next level.
“They will make mistakes at times and we’ve put a lot on them in terms of the physicality. The two of them were brilliant.”
O’Neill was also delighted for Brown, who said he had “really grown” into a senior role in the absence of injured Sunderland defender Dan Ballard.
“Three 90 minutes at this level is tough,” said O’Neill of the 28-year-old.
“He plays his club football in League One and he’s a better player than that.
“He brings a lot to the team. He was our most senior player tonight and he has really grown into that.”