Sopporo - Former champions England laboured to a bonus-point win against lowly Tonga in their opening Rugby World Cup match on Sunday, while fellow contenders Ireland threw down the gauntlet with an impressive victory against Scotland.
As it happened: England v Tonga, RWC 2019
Eddie Jones' side were left to rue a series of handling errors under the roof at the Sapporo Stadium and they only secured the vital bonus point for four tries with three minutes left on the clock, running out 35-3 winners.
A full-strength England side, seen as one of the sides to beat at this year's World Cup, took their time to get going against the physical Pacific islanders and were indebted to rampaging outside centre Manu Tuilagi for two first-half tries.
The result was never in doubt but England were far from their fluent best and will need to improve against Pool C heavyweights France and Argentina, with captain Owen Farrell admitting: "We've still got a lot more in us."
Jones called for his men to be "sharper with the ball" but insisted he was pleased with his players' efforts in the face of a tough challenge from Tonga, who were dismantled 92-7 by the All Blacks in the run-up to the tournament.
"We had to toil hard today and I was particularly pleased at the end of the game when we were under the pump a bit. We defended really well. That's two Tests now we haven't conceded a try so we're pretty happy with that," said Jones.\
In the day's marquee fixture, a dominant display by Ireland's forwards earned them an impressive bonus-point win over their Celtic rivals Scotland.
The emphatic 27-3 victory underscored their status as one of the pre-tournament favourites and sent out a message to southern hemisphere challengers New Zealand and Australia, who both won on Saturday.
World Player of the Year Johnny Sexton answered his critics after a worrying dip in form as Ireland shrugged off injuries to key players in their back line to seize the initiative in a tight group.
But it was the tight five forwards who broke Scotland's resistance, with pushover tries in the first half from lock James Ryan, prop Tadhg Furlong and hooker Rory Best.
Scotland had lost six of the previous seven games against the Irish but scented an upset in Yokohama as coach Gregor Townsend named the most experienced Test team in Scottish rugby history with an astounding 630 caps in the starting XV.
But heavy rain in Yokohama hampered Scotland's handling as their backs studded with British and Irish Lions failed to fire.
"That was a good start for us but we know... how much we need to improve going forwards," said skipper Best.
Coach Joe Schmidt refused to look too far ahead at a potential quarter-final clash with South Africa and said his team were "light heavyweight or middleweight" compared to the "heavyweight" Springboks and All Blacks.
But Townsend admitted: "We have to play much, much better in our next three games if we are going to make it out of our pool."
The first game of the day saw an unconvincing 47-22 win by Six Nations whipping boys Italy over Namibia, the lowest ranked side in the competition.
That match saw Italy's talismanic captain Sergio Parisse make history as only the third man to play in five World Cups but it was an error-strewn game to forget in at times torrential rain and fierce winds.
"We'll have to move on from that pretty quickly. It wasn't very pretty. There's too many errors in it," said Ireland coach O'Shea while Parisse agreed it was "not maybe a really nice match to see".
Sunday's matches come after three pulsating games the previous day when Australia overcome a feisty Fiji, France pip Argentina 23-21 and the mighty All Blacks beat the Springboks.
All the top teams have now taken to the pitch except Six Nations champions Wales, whose preparation was thrown into chaos by the expulsion of attack coach Rob Howley over betting allegations.
They play Georgia in a Pool D clash on Monday.
A powerful typhoon expected to pass between Japan and the Korean peninsula largely spared the matches, although there were squally moments in the Italy match and rain for Ireland-Scotland.
Tries: Manu Tuilagi (2), Jamie George, Luke Cowan-Dickie
Conversions: Owen Farrell (3)
Penalties: Owen Farrell (3)
Penalty: Sonatane Takulua
15 Elliot Daly, 14 Anthony Watson, 13 Manu Tuilagi, 12 Owen Farrell (captain), 11 Jonny May, 10 George Ford, 9 Ben Youngs, 8 Billy Vunipola, 7 Sam Underhill, 6 Tom Curry, 5 Maro Itoje, 4 Courtney Lawes, 3 Kyle Sinckler, 2 Jamie George, 1 Joe Marler
Substitutes: 16 Luke Cowan-Dickie, 17 Ellis Genge, 18 Dan Cole, 19 George Kruis, 20 Lewis Ludlam, 21 Willi Heinz, 22 Henry Slade, 23 Jonathan Joseph
15 David Halaifonua, 14 Atieli Pakalani, 13 Siale Piutau (captain), 12 Cooper Vuna, 11 Viliami Lolohea, 10 Kurt Morath, 9 Sonatane Takulua, 8 Maama Vaipulu, 7 Zane Kapeli, 6 Sione Kalamafoni, 5 Halaleva Fifita, 4 Sam Lousi, 3 Ben Tameifuna, 2 Sosefo Sakalia, 1 Siegfried Fisi'ihoi
Substitutes: 16 Siua Maile, 17 Latu Talakai, 18 Ma'afu Fia, 19 Dan Faleafa, 20 Nasi Manu, 21 Leon Fukofuka, 22 James Faiva, 23 Nafi Tu'itavake