New Roma recruit Hector Moreno pounced in stoppage time to snatch a 2-2 draw in Kazan, where Cedric Soares appeared to have sealed the points for the European champion.
It was the second time Juan Carlos Osorio's men came from behind in an undulating match, with Hernandez heading home in the 42nd minute after Ricardo Quaresma opened the scoring.
The Gold Cup holder is heavy favourite heading into its next Group A assignment at Fisht Stadium, with New Zealand nursing a 2-0 defeat to Russia on Saturday – a match that saw the All Whites tick past 500 minutes without a goal at the Confederations Cup
"Coming from behind leaves you with a different feeling," Hernandez said. "We want to look at it with tranquillity as we don't know if this point will be good or not until we play the remaining two group stage matches and we know if we qualify for the semi-finals.
"If we don't then this point will mean nothing because all we want is qualifying for the next stage and to end up winning the tournament."
Upsetting the host on the opening night was widely viewed as the best chance for tournament outsider New Zealand to get some points on the board with a famous scalp, its overall ambitions lying somewhat more modestly.
However, goalkeeper Stefan Marinovic has sought to rally his team-mates and insists any negativity in the camp will not be tolerated.
"Of course belief is still there," said the 25 year-old, who plays for third-tier German side Unterhaching. "No one in this team is negative and never has been.
"That is one thing that if you want to be in the All Whites, you need to have that belief.
"You need to always be positive. You want to be here. If you have got a negative attitude then you don't deserve to be here."
New Zealand boss Andrew Hudson could seek to rebalance his team after the inclusion of attack-minded duo Kosta Barbarouses and Marco Rojas left it lacking midfield numbers against Russia's early onslaught.
Opposite number Osorio has a long-established commitment to rotating his line-up, often to the chagrin of Mexican fans and pundits, and the combination of a swift turnaround in playing time, alongside the relative weakness of the opposition, means he should be expected to ring the changes once more.