Wales manager Chris Coleman was stunned by his side’s “absolute hammering” at the hands of Serbia.
The visitors came into the Group A qualifier on a poor run of form under Coleman, suffering four straight defeats and failing to score a single goal – only to see a multitude of defensive errors lead to the country’s worst defeat since the 7-1 loss to the Netherlands in 1996.
And the former Fulham boss was shocked by the result and by the manner of his side's performance, admitting it was unacceptable.
He told Sky Sports "Obviously I did not see it coming."
"We knew it would be difficult coming here but on the back of Friday's performance against Belgium we thought we could get something but we can't accept that level of performance.
"To say it is disappointing is an understatement. We have to do much better than that and we are capable of doing much better.
"To lose 6-1 is an absolute hammering and we can't ignore that, the manner of the performance was particularly disappointing."
Coleman was, unsurprisingly, particular critical of his teams' defending after seeing the hosts take advantage of a number of defensive mistakes, as well as questioning their perseverance.
He added: "At times it was men against boys, the goals we conceded were criminal really and the individual errors were disappointing.
"At this level you cannot gift teams goals, you have to at least be hard to beat and play with a bit of pride and we didn't do that. We caved in.”