For Sheffield United, that moment came just before half-time in a 2-1 home defeat to Leicester City.
In front of a Bramall Lane crowd buoyed by an encouraging haul of four points from the opening two games, the home side had held their own against the Foxes for 38 hard-fought minutes.
United had rarely looked in any trouble against an attacking trio that typifies the quality that exists in the top flight.
Then, though, came a passage of play that underlined just how ruthless the Premier League can be.
Chris Basham had the ball at his feet when he cut inside, chiefly to get away from Ayoze Perez.
The former Newcastle United man spotted the potential of the situation straight away and chased after the defender, eventually nicking the ball away.
Then, the other two members of Leicester’s deadly trio got to work. James Maddison collected and released Jamie Vardy with the type of dink over the top the boyhood Wednesday fan has made his food and drink for years.
Sure enough, Vardy’s finish was firm and true, giving Dean Henderson no chance in the home goal.
It was one of only eight touches by the Sheffield-born striker in the first half - the lowest of all 22 players on duty - but typically clinical.
For United, falling behind took some time to get over. Leicester’s attacking trio combined again soon after half-time and could have doubled their side’s advantage but Perez’s effort went across the face of goal.
The home side needed a lift and it came via the introduction of Oli McBurnie and Billy Sharp from the bench.
A neat passing move on the edge of the area saw Sharp collect the ball from Luke Freeman and then find Oliver Norwood.
He, in turn, spread the play to George Baldock whose perfectly weighted cross was glanced in by McBurnie.
The £17m record buy almost had another midway through the second half when Kasper Schmeichel flapped at a Freeman cross and the ball bounced kindly for the Danish international.
It was a let-off that the Foxes capitalised upon, and again it was a touch of Premier League quality that proved United’s undoing.
Harvey Barnes’ half-volley was so powerful that Henderson barely stood a chance in the home goal as the ball flashed into his net to seal all three points for the Foxes.