Gareth Southgate this week warned against any sense of complacency in future England matches with their place at next year's World Cup almost assured. Damian Szymanski's stoppage-time equaliser to earn Poland a 1-1 draw on Wednesday should ensure it doesn't materialise.
England were on the brink of passing a significant test against combative hosts roared on by 56,212 supporters who came to worship Robert Lewandowski but looked like leaving with only grudging admiration for Harry Kane.
The Tottenham Hotspur striker netted his 41st international goal -- taking him clear as England's fifth-highest goal scorer in history -- courtesy of a superb, swerving 32-yard strike that was the physical manifestation of his team gradually wearing down their opponents before landing what appeared to be a knockout blow. However, Bayern Munich forward Lewandowski had the last laugh, utilising a rare moment of freedom in England's penalty area to lift a teasing cross to the far post where Szymanski towered above Luke Shaw to plant a header past Jordan Pickford.
In the context of World Cup qualifying Group I, the damage is minimal for the Three Lions. They remain four points clear of Albania with four games remaining, two of which are almost certain victories against minnows Andorra and San Marino. But minds are already drifting to Qatar and the tournament England originally earmarked for success many years ago by the Football Association -- a target that feels within reach after this summer's sojourn to the Euro 2020 final.
However, to go that one step further, they must learn the lessons from nights like this. Nobody should expect a radical evolution in this team so soon after the Euro final given 10 of that starting lineup began in Warsaw, but the solitary change was significant: going to a back four to accommodate Jack Grealish was a call many wanted Southgate to make during the last tournament.
Those who want the 50-year-old to unleash more of his squad's attacking potential should be encouraged that he entrusted his players to express themselves in a 4-2-3-1 shape in such a hostile environment. That approach contributed to a more open encounter, albeit one short on goalmouth action particularly in a first half memorable more for the undercurrent of antipathy that ran through it before bubbling over at half-time.
Poland were out to hassle and antagonise from the outset. Kamil Glik was irritator-in-chief, sparking a melee at the end of the opening period by pinching the skin under Kyle Walker's chin during a break in play prior to a Poland free kick. Walker outmuscled Glik at the subsequent set piece, sparking a clash that eventually ended with German referee Daniel Siebert booking both Glik and Harry Maguire.
He could easily have had his cards on display earlier given Grealish and Kane in particular were on the end of several strong challenges, but England were holding their nerve well.
It should be remembered that those searching for holes in England's form at the Euros point to the fact they played six of their seven games at Wembley. Their only trip was to face Ukraine in Rome, at a venue with a reduced capacity yet still heavily populated by England fans.
Like in Budapest against Hungary six days earlier, this couldn't have been more of a contrast. Yet England gradually began to assume a level of control, albeit bereft of clear opportunities and therefore requiring a moment of brilliance from Kane to break the deadlock.
Picking the ball up in a central position with 18 minutes left, Kane tried his luck, cutting across the ball with a fierce right-footed strike that created enough swerve to send it past Wojciech Szczesny. Kane has now scored in 15 consecutive qualification matches, a measure of his remarkable consistency that will surely see him surpass Wayne Rooney's all-time record of 53 goals in the next couple of years.
However, England did not press home their advantage. Poland made five changes -- including three after they went behind -- in an effort to generate some momentum. In a pattern reminiscent of England's defeat to Italy in the Euro final, they began to drop deeper, relinquishing territory and initiative.
Pickford almost gifted Poland an equaliser when firing a clearance straight at the onrushing Karol Swiderski only to gratefully scamper back towards goal and grab the loose ball before it crossed the line. A brilliant touch from Lewandowski then created an opening from which he fired wide, but the warning signs were there. In the second minute of added time, Lewandowski turned provider for Szymanski, a substitute, to equalise.
Southgate didn't make a single change all evening.
"We were in total control of the game and to bring players into that moment when everybody was performing to a good level and we were in control of possession, you can put players into the game who have had to sit in the stand and it is not so easy to come in in those latter stages," he explained. "There were a couple of times where we looked at it and said 'no, we're doing well, no problem.'
"We were going to refresh the wide players right at the end, but really that would have been to run the clock down as much as anything. But before we could get them in, we conceded the goal and once we conceded the goal, again we didn't think that was a good moment to make a change."
It is difficult to escape the conclusion that some sort of intervention would have at least disrupted Poland as they began to find a rhythm. Better teams will pose the same threat, as Italy did, and Southgate will need to be alive to it.
That said, England end the September internationals with seven points and a firm grip on Group I, albeit surrendering their 100% record.
"We couldn't be sure what reaction we would have after the summer but we have had a really positive one and I think the two away games, we've given in the main very mature performances," added Southgate.
They are on track, but complete performances are what will be required at the World Cup.