Ireland eventually cruised past Romania by 44-10 in front of a record crowd for a Rugby World Cup match at Wembley Stadium on Sunday.
It took the Six Nations champions over 60 minutes to notch up their bonus point try before they ran riot late on, watched by 89,267 fans of which well over half were present wearing green.
Ireland wingers Keith Earls and Tommy Bowe both scored either side of half-time and the Pool D favourites never looked out of control at any moment, even if it took longer than planned to ensure they took away maximum points — a compliment to Romania who were dogged and snuffed out a number of Irish attacks without troubling the scoreboard themselves until a late consolation try from Ovidiu Tonita.
The only real negative for Ireland was the withdrawal of Rob Kearney after he came on in the second half as a replacement, although he left the field unassisted.
Chris Henry and Simon Zebo were both noticeable standouts for Ireland, who ultimately finished with six tries.
Everybody but referee Craig Joubert thought Zebo has produced the try of the tournament after a brilliant score in the corner following some of his trademark footballing skill, but a look from the TMO confirmed that his foot had been in touch.
Ireland would have to wait a little longer, not too long though, as Tommy Bowe ended his seven-game try drought with an inch-perfect finish by the corner flag after Ireland exploited an overlap.
Madigan's second penalty made it 13-3 as the Six Nations champions flexed their muscles, finding complete control at the lineout.
Zebo had provided the final pass for Bowe's try and was once more the provider when Ireland struck again, floating out a perfect pass to his Munster team-mate Keith Earls who dipped his head and sprinted for the line.
It took 33 minutes until the game's first scrum, normally Romania's stronghold, but they were well pressured by Ireland who completely dominated possession (71 per cent) and territory (76 per cent) throughout the first half.
Yet their lead was only 15 points going into the break up 18-3 thanks to those tries from their two wingers.
It took all of three minutes into the second half for Earls to strike again. Eoin Reddan's low rolling kick bounced up perfectly for Earls to rush behind the Romania defence and dot down, with Madigan landing the wide conversion. In the process Earls levelled Brian O'Driscoll's record of seven Rugby World Cup tries for Ireland.
Credit to Romania, their heads never dropped. Adrian Apostol's break down the touchline sparked a long attack in Irish territory, only for Richardt Strauss to strike at the breakdown with a turnover.
Earls was denied the chance of a hat-trick after going off for a Head Injury Assessment.
Wembley's mexican wave produced such volume that Romania had to form a huddle in order to call their lineout, but they continued to frustrate with key turnovers deep in their own 22.
They were close to going down to 14 men after Florin Ionita's dangerous tackle in the air on Paddy Jackson, only resulting in a penalty, but it set up Ireland in the Romanian 22 and ultimately led to their bonus point try.
Reddan's loop with Jackson created the space out wide for Bowe to grab his second try, shortly followed over by replacement Rob Kearney after another Zebo break created by Ireland's clever runners in their backline.
Ireland's sixth try was all about forward power as Henry came up with the ball after an unstoppable rolling maul.
Veteran lock Tonita came up with a deserved score for Romania after their defensive work and kept Ireland from scoring a seventh try into overtime, but the job was long done for Ireland as they take ten points from their first two games.
Man of the Match: A close call as Ireland's back three all shone but Simon Zebo was all class for Ireland, providing two assists and close to pulling off a spectacular score of his own.
Moment of the Match: Not actually during the 80 minutes but afterwards following Romania's lap of the pitch to warm applause from the crowd, scrum-half Florin Surugiu proposed to his girlfriend out on the field, who said yes!
Villain of the Match: Nothing nasty to report.
The scorers:
For Ireland:
Tries: Bowe 2, Earls 2, Kearney, Henry
Cons: Madigan 4
Pens: Madigan 2
For Romania:
Try: Tonita
Con: Vlaicu
Pen: Calafeteanu
Yellow Card: Gal
Ireland: 15 Simon Zebo, 14 Tommy Bowe, 13 Jared Payne, 12 Darren Cave, 11 Keith Earls, 10 Ian Madigan, 9 Eoin Reddan, 8 Jamie Heaslip, 7 Chris Henry, 6 Jordi Murphy, 5 Devin Toner, 4 Donnacha Ryan, 3 Nathan White, 2 Richardt Strauss, 1 Cian Healy.
Replacements: 16 Sean Cronin, 17 Jack McGrath, 18 Tadhg Furlong, 19 Paul O'Connell, 20 Sean O'Brien, 21 Conor Murray, 22 Paddy Jackson, 23 Rob Kearney
Romania: 15 Catalin Fercu, 14 Adrian Apostol, 13 Paula Kinikinilau, 12 Csaba Gal, 11 Ionut Botezatu , 10 Michael Wiringi, 9 Valentin Calafeteanu, 8 Daniel Carpo, 7 Mihai Macovei (c), 6 Valentin Ursache, 5 Ovidiu Tonita, 4 Valentin Poparlan, 3 Paulica Ion, 2 Andrei Radoi, 1 Andrei Ursache
Replacements: 16 Mihaita Lazar, 17 Otar Turashvili, 18 Alexandru Tarus, 19 Johan Van Heerden, 20 Stelian Burcea, 21 Florin Surugiu, 22 Florin Ionita, 23 Florin Vlaicu
Referee: Craig Joubert (South Africa)
Assistant Referees: Leighton Hodges (Wales),Romain Poite (France)
TMO: Shaun Veldsman (South Africa)
It was a match of two halves as Vern Cotter's charges, who were well off the pace in the opening 40 minutes, found their form as they moved top of Pool B.
Gareth Davies' spectacular try for Wales with ten minutes to go flipped the contest on its head after they had trailed for over 40 minutes.
After Wales' comeback win over England, Australia continued to ease into the competition, scoring 11 tries against the pool's weakest side.
A week on from their shock loss to Japan, the Springboks knew that it was win or bust for them, and they came out with intensity from the off.
Both teams crossed for two tries but it was the boot of pivot Tommaso Allan that proved the difference as the Azzurri picked up their first victory of the pool.
Los Pumas, who lost their tournament opener to New Zealand last Sunday, outscored their opponents by seven tries to nought and their fly-half Nicolas Sanchez impressed with his goalkicking, finishing with a 15-point haul, via two penalties, three conversions and a drop goal.
In the first meeting between the two teams, there was only ever going to be one winner, and the All Blacks were thoroughly professional as they downed their overmatched opponents scoring nine tries in total.
After being thoroughly outplayed at the breakdown, France needed a ten-minute spell with an extra man to finally break Romania down in the first half, with Sofiane Guitoune and Yannick Nyanga crossing to give them a 17-6 half-time lead.
While they didn't pick up the try bonus-point like England five days ago, it was a streetwise pool start from the recent Rugby Championship winners in Cardiff.
Five tries in the second half, including two for Mark Bennett, wrapped up a convincing win at the end for the fresher Scots in their first game, with the outcome always set to hinge on how quickly Japan had recovered both mentally and physically from last Saturday's spectacular triumph over South Africa.
In front of a world record crowd, Argentina dominated for 50 minutes, taking advantage of two All Black sin-binnings as they played some scintillating rugby.
Again injuries have soured the Welsh day as full-back Williams and centre Allen both limped off with respective issues. Williams' however did not seem too serious as he fought with the medical staff to remain on the field. It's not an ideal situation though with a crunch match against England ahead next weekend.
Samoa were always ahead on the scoreboard thanks to tries from Nanai-Williams and their captain Ofisa Treviranus, along with the boot of fly-half Tusi Pisi.
The Toulouse winger went down clutching his knee 15 minutes into the second half, and judging by his tears on the sidelines, his tournament is surely over.