Ireland coach Declan Kidney praised his players after their seven-try demolition of a feeble Argentina in Saturday's crucial Test in Dublin.
The 46-24 victory secured Ireland's top-eight ranking ahead of next month's draw for the 2015 World Cup.
"It was a good day. It's amazing when a few things fall your way the difference it can make," said Kidney, who was under pressure going into the contest.
"Getting those (four) tries in the first half gave us confidence."
Impressive debutant Craig Gilroy, Jonathan Sexton, Richard Strauss and Simon Zebo scored Ireland's first-half tries.
"The first half display gave us that little bit of confidence going into the second half," Kidney added.
"And while we fell away at the end a little bit, it was a great day for us.
"Small things can make a huge difference. You look at how it started for Argentina. We kicked out on the full (at the start). They got a penalty and the ball came back off the post.
"These games are on thin margins. We had a few that went against us this year but today a few things went our way."
Kidney was delighted with his team's second-half display after losing their way following the half-time break in the 16-12 defeat by South Africa two weeks ago.
"We knew it was vital after the South Africa match that we came out in the 10 minutes after half-time.
"(For the fifth try) The boys saw there was a bit of space in behind and Tommy (Bowe) took it at a bit of pace."
Despite the win, Kidney insisted that his players would "not be getting carried away" after the impressive display.
"We didn't get despondent two weeks ago (after the South Africa defeat). We'll enjoy tonight but we know we have a lot of consistency to work on.
"One good day doesn't make up for a whole season and for what has happened in the last 12 months."
Kidney added that the displays of youngsters such as Gilroy and Zebo emphasised the "good work being done" in the Irish provinces.
"Craig did well with Simon. Overall, we had about four or five new caps over November and four or five other guys were involved who had only a handful of caps between them going into the series.
"I thought Chris Henry was exceptional today and there are quite a number of young lads coming through.
"There were 17 changes in the group of 30 (this week) from the squad that went to the last World Cup."
Test debutant Gilroy predicted an exciting time for the Irish team after the impressive victory.
"Everything clicked well," added the Ulster wing.
"I was so nervous coming into the game and I'd got a number of messages from family and friends. It meant a lot."