Hanover - Northern Ireland manager Michael O'Neill says a rampant Germany are almost impossible to stop after the world champions' dominant 2-0 win in a World Cup qualifier.
The Germans made it three wins from three qualifiers for the 2018 finals in Russia with first-half goals by Julian Draxler and Sami Khedira sealing the routine win in Hanover on Tuesday.
Germany are yet to even concede a goal in their qualifiers for Russia 2018 and look in ominous form.
"We came here with a plan to try and nullify a fantastic team with fantastic players, which is only good if you can keep them to zero," said O'Neill, whose side has four points from three games and faces an uphill battle to get to the World Cup.
"We conceded the first goal, it was a great finish from Draxler, but it was disappointing to lose the second goal from a corner.
"We looked like we could get a goal when we countered in the first-half and we showed a good spirit to keep them to two goals.
"But I'm not sure there is a system which can contain Germany at this moment in time.
"It's not just the tactical side of it, it's the enormous quality and athleticism of their players."
Germany coach Joachim Loew revealed he told his side they need to be "ruthless" and qualify for Russia as quickly as possible.
"This was a fairly effortless victory, I have to admit," said Loew. "We took a quick lead and sat back after that. Ireland defended deep, it felt like a 1-9-1 formation at times."
But Loew rejected the notion that his side are a class apart, especially after the disappointment of their semi-final defeat to France at Euro 2016.
"There have been teams who have managed to stop us, but the fact is we have managed to reach a level of domination," said Loew.
"We have a great level of variability with players changing positions to confound the opposition.
"We have different players scoring goals and we have managed to get a lot of depth to our game, plus we have a very settled side.
"We have really worked hard to get this level."
But Loew cautioned that wins against Norway, the Czech Republic and now Northern Ireland meant Germany had not faced "category one" sides.
Loew will travel to Russia in November for a fact-finding trip ahead of Germany's involvement in the Confederations Cup next year and in anticipation of qualifying for the 2018 World Cup.
Captain Manuel Neuer says however that there is room for improvement.
"We know from the last European championships that anything can happen and we still have dangerous games ahead of us," he warned.