Ireland coach Eddie O'Sullivan believes the minnows of this World Cup have shown a marked improvement in the way they play the game.
However, he also believes the top teams are drawing further away and the gap is steadily growing in terms of the gulf in class.
O'Sullivan, in chirpy mood at his team's headquarters in Terrigal, said: "Heavyweights like New Zealand, England and Australia are pulling further away from the rest.
"They are now standing alone at the top of the tree. However, there is also a marked improvement in the lesser lights.
O'Sullivan (centre) is happy with Ireland's Cup start
"For example, while both England and South Africa scored heavily against both Uruguay and Georgia, it was not all plain sailing.
"These teams are now very combative, and very physical. We also experienced that against Romania.
"We defeated them 39-8 last year in Limerick, but we had a far tougher job last week in dispatching them even though we put 45 points on them.
"Like all games now against the so-called minnows, that match was very physical and the players knew they were in a game.
"It was the same for England against Georgia. All these teams now play a hard uncompromising game. They tackle harder, their defences are better organised, and they kick their goals."
Ireland come up against more minnows in Namibia, their next Pool A opponents on Sunday.
O'Sullivan insists there are no injury concerns despite Keith Wood and David Humphreys receiving knocks in the win over Romania.
"The victory against Romania was a very positive start for us," said O'Sullivan. "I was particularly pleased the way players who were out of action for a long time came back strongly.
"I thought Shane Horgan had a quite brilliant game, while it was good to see John Hayes playing his first match since February, and looking as if he had not been a way.
"But there is a very good feeling in the camp. Everybody is training extremely hard and well, and the mood is excellent. That makes for a happy squad."
O'Sullivan also entered the debate over midfield blocking in earlier games.
The Wallabies were heavily criticised by both England and Argentina for what both sides deemed illegal blocking in their 24-8 win over the Pumas.
And O'Sullivan added: "It's something we will have to be careful about. I thought Australia were guilty of blocking against Argentina. I also thought Japan's try against Scotland should not have been allowed.
"I thought a Scottish midfield player was completely taken out of the game. He landed on his back and Japan engineered the extra man to score.
"Argentina seemed completely overawed by the occasion. They just never got going. They are probably saving everything for us."