Ireland and Wales couldn't be seperated after 80 minutes, the two sides drawing 16-16 at the Aviva Stadium in Dublin.
The first draw between these two nations since 1974 hands them both just one point after both failed to find a late breakthrough with the clock ticking down after an exhausting physical battle.
Ireland through Conor Murray's try and two Jonathan Sexton penalties raced out into a 13-0 lead, but it's a testament to the experience of Wales in this tournament that they never panicked, chipping their way back to level the scores ten minutes into the second half.
Jamie Roberts' spearheaded an impressive defensive effort from Wales, a second-half tackle on Robbie Henshaw angering the crowd despite being clearly legal.
Unglamorous perhaps, but no less impressive as his side gradually ground down Ireland's lead before Rhys Priestland's penalty gave them a late advantage. Sexton however held his nerve to level the scores once more as the game ended 16-16.
CJ Stander started brightly in his long-awaited debut for Ireland after belting out the national anthem before kick-off, carrying hard to force a penalty against Wales which Sexton converted after six minutes for a 3-0 lead.
Persistent pressure from the hosts forced Wales into putting in a high number of tackles, eventually resulting in a penalty against the visitors for not rolling away as Sexton doubled his tally.
The early departure of in-form Dan Biggar seemed crucial for Wales, Rhys Priestland entering the fray months after his international future looked momentarily over following his move to Bath.
The momentum of the first half hour continued to flow Ireland's way, culminating eventually in the game's first try.
Ireland's big runners were effective and after carries from Robbie Henshaw and Stander, Murray darted his way over around the fringes for an efficient score.
That bright start however nearly came undone after Keith Earls appeared to make a dangerous tackle on Liam Williams, a late call-up at full-back for Gareth Anscombe. The Ireland winger escaped a yellow card but Priestland did convert the resulting penalty to put Wales on the board.
Taking the initiative Wales continues to hit back and despite an unsteady scrum, Taulupe Faletau was able to power his way over from close-range, having too much energy and strength for Sexton as Ireland looked weary towards the end of the first half — leading 13-10 at the break.
Priestland's early drop goal attempt at the start of the second half fell wide but he made no mistake with a penalty not long after to tie the scores at 13-13.
As the physicality rose so did the number of handling errors from each side in a contest now filled with tension, the Dublin crowd bursting into a rare roar when Sexton cut through the defensive line and delivered a perfect pass wide to Andrew Trimble only for the winger to be bundled into touch.
A monster set of phases from Wales in Irish territory, 28 in total, resulted finally in a penalty at the ruck for Wales to take the lead for the first time with eight minutes remaining. Priestland rose to the challenge, converting to make it 16-13.
Naturally based on how close the contest had been Ireland were given an immediate chance to reply, the Aviva Stadium descending into a hush as Sexton delivered to make it all square.
Priestland missed once again going for a drop goal to snatch victory with two minutes left and Ireland had a chance to kick the ball out from a scrum with time up on the clock, but instead went for the win.
There was to be however no final score, Ireland and Wales settling for a 16-16 draw and nursing some battered bodies heading into Round Two.
Man of the Match: A superb debut for CJ Stander but the tackling of Jamie Roberts was so impressive for Wales in midfield.
Moment of the Match: After all those phases Rhys Priestland finally put Wales in front with less than ten minutes to go, his penalty appearing to complete an impressive comeback until Sexton responded.
Villain of the Match: Nothing nasty to report.
The scorers:
For Ireland:
Tries: Murray
Cons: Sexton
Pens: Sexton 3
For Wales:
Tries: Faletau
Cons: Priestland
Pens: Priestland 3
Ireland: 15 Simon Zebo, 14 Andrew Trimble, 13 Jared Payne, 12 Robbie Henshaw, 11 Keith Earls, 10 Jonathan Sexton, 9 Conor Murray, 8 Jamie Heaslip, 7 Tommy O'Donnell, 6 CJ Stander, 5 Devin Toner, 4 Mike McCarthy, 3 Nathan White, 2 Rory Best (c), 1 Jack McGrath
Replacements: 16 Sean Cronin, 17 Jerry Cronin, 18 Tadhg Furlong, 19 Donnacha Ryan, 20 Rhys Ruddock, 21 Kieran Marmion, 22 Ian Madigan, 23 Dave Kearney
Wales: 15 Liam Williams, 14 George North, 13 Jonathan Davies, 12 Jamie Roberts, 11 Tom James, 10 Dan Biggar, 9 Gareth Davies, 8 Taulupe Faletau, 7 Justin Tipuric, 6 Sam Warburton (c), 5 Alun-Wyn Jones, 4 Luke Charteris, 3 Samson Lee, 2 Scott Baldwin, 1 Rob Evans
Replacements: 16 Ken Owens, 17 Gethin Jenkins, 18 Tomas Francis, 19 Bradley Davies, 20 Dan Lydiate, 21 Lloyd Williams, 22 Rhys Priestland, 23 Alex Cuthbert
Referee: Jérôme Garcès (France)
Assistant referees: Glen Jackson (New Zealand), Ben O'Keeffe (New Zealand)
TMO: Graham Hughes (England)
Eddie Jones hinted it wouldn't be pretty but a victory is all the English wanted to start their new era on a positive note after a poor World Cup.
Virimi Vakatawa crossed on his debut as France outscored their visitors three tries to two, but Sergio Parisse's late drop-goal attempt nearly snatched victory for the Azzurri, only for his effort to miss.
Despite the wet and windy conditions, the Maori All Blacks opted to run the ball but they committed too many unforced errors which the Baa-baas capitalised on.
JP Pietersen and Eben Etzebeth scored a try in each half for the Springboks, while Handré Pollard slotted four penalties and a conversion before Habana was removed with quarter of an hour remaining.
The Wallabies bravely defied the odds to claw their way back from 21-3 down to make it 21-17 in the second half, but it wasn't to be their day.
The Wallabies went over three times in the first half and despite the excellent goal-kicking of Nicolás Sánchez, Ashley-Cooper's third, following a magnificent break from Drew Mitchell, sealed the win.
The All Blacks are still on track to become the first team to defend the world title as they will now face the winners of Sunday's second semi-final between Argentina and Australia.
Scotland were outstanding and went desperately close as Mark Bennett's interception score looked to have clinched an enormous upset, after opportunist tries from Peter Horne and Tommy Seymour kept them in the hunt.
Fully refreshed from a game's rest in their final pool match, los Pumas' first XV won the physical battle and fully deserved their passage into the last four, showing a great deal of attacking prowess to prove they are an ever-evolving outfit.
The All Blacks set up a mouthwatering semi-final thanks to a hat-trick from Julian Savea, never giving France a sniff of a third World Cup upset as they claimed the biggest win in World Cup knock-out history.
Springbok skipper Fourie du Preez scored in the 75th minute to snatch victory in an epic game that could have gone either way.
Nothing has epitomised the 2015 Rugby World Cup quite like the performances of the emerging nations and it was fitting that a packed house at Kingsholm saw Japan, the heroes of the first weekend of the tournament, see off the challenge of a muscular USA side in a game polarised by the power of the States versus the technical excellence of their opponents.
Joe Schmidt's side will likely be without Paul O'Connell, Jonathan Sexton, Peter O'Mahony and Sean O'Brien for their quarter-final against Argentina next Sunday after a brutal encounter.
The four-tries-to-three victory ensures the Azzurri qualify directly for Rugby World Cup 2019 in Japan as they finish third in Pool D, with two wins from their four games.