Any pre-World Cup nerves Ireland had as they headed into their crunch group opener against Scotland were quickly settled as they produced an impressive, confident and ruthless display to win 27-3 on Sunday.
Scoring four tries as they did through James Ryan, Rory Best, Tadhg Furlong and Andrew Conway to secure a bonus point and take control of Pool A, Ireland delivered on their promise to hit form when it mattered most.
The number one ranked side coming into the tournament lived up to that debatable position with an impressive first half display against a Scottish side who simply had no answer to the power and precision offered up by an Irish pack led by Ireland’s oldest player to take part in a World Cup, Rory Best.
The hooker went the full 80 minutes, led by example, had 100 per cent return from the lineout and scored a try.
Not bad for the 37-year-old veteran who surely now has silenced the critics who have recently tried to put the Banbridge clubman down.
It was a stand-out performance along with that of fellow Ulsterman Iain Henderson in the second row with some meaty tackles, a menace around the breakdown area and making the break which saw fellow lock James Ryan go over for a try.
The other eye catching displays came from Josh van der Flier, his red scrumcap seemed to be everywhere on the pitch and replacement Chris Farrell, who was a demon in defence and a tasty repertoire of line breaks, carries and passes when he came on for Bundee Aki. Ireland head coach Joe Schmidt probably reflected the mood of all when he gave a tense pre-game pitchside interview - but the big smile post-match equally reflected the mood of the country - Ireland bang on course to make the quarter-finals barring any major upsets against hosts Japan on Saturday and then facing lowly ranked Russia and Samoa.
There will certainly be some concern around outhalf Johnny Sexton with the Leinster man struggling with a groin problem during the first half before finally being hauled off after the fourth try was scored early in the second.
Aki and Peter O’Mahony suffered HIAs and the short turnaround to the next game may come too early for them. But the question marks around Ireland’s potential lack of strength in depth in some areas were not raised in this impressive start. Missing Rob Kearney, Keith Earls and Robbie Henshaw for the opening game in Yokohama, Jordan Larmour, Andrew Conway and Garry Ringrose came up trumps.
Jack Carty - on for Sexton - also delivered and, of course that man Farrell, the Fivemiletown born lad showing why he got the call-up to the final squad.
Crucially for Ireland, without getting overly confident or complacent at this early stage, Schmidt can manage his side carefully through the remaining pool fixtures.Japan picked up a bonus point win over the Russians and while they are not likely to trouble the men in green on Saturday morning, get through that one and Ireland should not be troubled in securing top spot in the group. For the hosts - and indeed Samoa - they will now look to target the Scots and could well present a serious challenge to who would take second spot in the Pool and a last eight berth.
Dangerous as it is to look too far ahead (and after only three days of tournament play), South Africa - following their loss to New Zealand in the Pool B opener on Saturday - are likely to be the Irish opponents in the quarter-finals.
In the warm-up games, after a thumping by England at Twickenham, Ireland began to display glimpses of the Grand Slam winning form of 2018.
That continued against Scotland and confidence will have grown further after the performance and result. There is still room for improvement, but there is no doubt Ireland are serious contenders at this global event.
Meanwhile, what had gone previously on the opening weekend of the tournament in Japan had certainly whet the appetite - but be warned not all the fixtures ahead will be as intense.
Japan and Russia had served up an average fayre after the simplistic, but impressive, opening ceremony, the hosts finally shaking off the nerves to take a bonus point win as they bid to upset one of either Ireland or Scotland in Pool A and book a last eight spot.
Super Saturday arrived with several of those in the mix to lift the Webb Ellis Trophy involved. Australia survived a scare from Fiji to open their bid with a 39-21 win.
France and Argentina served up a cracking game, with the South Americans staging a dramatic comeback, but missing a last gasp long range penalty to lose by two points, 23-21.
This was as close to a knockout game as you could have in an opening Pool C match - a group that also contains England - only two of the three can progress to the last eight. The French had certainly fired a warning shot to the main challengers, but they will need to find a way to produce more than a quality 40 minute performance if they make it through to the knockout stages.
Then came the main course. New Zealand v South Africa, the defending double champions against the side widely tipped to strip the All Blacks of the crown. The Springboks took the challenge to the holders, but the Kiwis pounced in emphatic fashion once they got the opportunity and raced into what was an uncatchable lead before going on to win by a 10-point margin.
England produced a workmanlike display to beat Tonga 35-3 in Pool C, scoring four tries in the process.