England put themselves within sight of the World Cup quarter-finals with a comfortable bonus-point victory over Romania in Dunedin.
Mark Cueto scored a first-half hat-trick and fellow wing Chris Ashton a brace to put them 34-3 up at the break.
Ashton completed his hat-trick after the restart as England ran in 10 tries in all in a much-improved performance.
If Scotland beat Argentina, the Scots and England will both qualify, their meeting deciding the pool winner.
The winner of the group will play the runner-up from Pool A - likely to be France or New Zealand.
While England's record 134-0 win against Romania, in 2001, never looked like being threatened at Otago Stadium, it was an encouraging display after stuttering and indisciplined wins over Argentina and Georgia in their first two games.
Fly-half Jonny Wilkinson put his below-par performance against Argentina behind him with a fine first-half showing, slotting four kicks from six and controlling his back-line with aplomb, while England's three-quarters were brimming with life and clinical with their execution.
Up front, skipper and open-side Lewis Moody looked almost back to full fitness, while England's set-piece was barely troubled, albeit against a Romania side showing 11 changes from that beaten by Argentina earlier in the week.
England were on the scoreboard after only one minute, Wilkinson, who missed five penalties in his side's opener against the Pumas, knocking over a three-pointer from bang in front, despite boos from the crowd.
England looked to put width on the ball in the opening 10 minutes and when Wilkinson found Moody with a sweet flat pass to open up the Romanian defence, it should have led to the first try.
However, after an inside pass from Moody to Tom Croft and a surge from the England blind-side, number eight James Haskell was eventually pinged from in front of the posts for not releasing.
Tuilagi and Ashton started in lively fashion, centre Tuilagi doing what he does best, straightening and bursting into the line, and Ashton always looking to leave his wing and get involved in the action.
When Wilkinson found Ashton with another fizzing flat pass after 16 minutes, the Northampton man went flying through a hole in the Romanian defence and set up Cueto for a try in the corner.
Six minutes later Cueto went over for his second try after the recalled Mike Tindall found him with a perfectly-timed pass, before Ashton went on another dart, this time down his opposite wing, only for his speculative pass inside to be ruled forward.
Shortly after Cueto completed a hat-trick in the space of 11 minutes, diving over in the left-hand corner once again after more clinical interplay between backs and forwards.
Perhaps the best try of the match was scored by Ashton after 31 minutes, when he timed his run perfectly to latch on to an inside pass from Wilkinson and touch down under the posts.
Ashton only had to wait three minutes for his second try, lock Louis Deacon setting it up with a rollocking line-break, before Romania got on the scoreboard courtesy of a penalty from fly-half Marin Danut Dumbrava.
With half-time approaching, England rather switched off, but for the most part it was an improved first 40 minutes from Johnson's side, which came in for much criticism following stuttering displays in their first two games.
Toby Flood replaced Wilkinson at the break and scrum-half Ben Youngs scored almost directly from the restart, spotting a gap down the short side and linking well with Tuilagi down the right flank, and nine minutes later full-back Ben Foden extended England's lead following a bullocking line-break by Tuilagi.
When Romania did manage to string together some phases midway through the first half, England's discipline held firm, although on the whole it was a less focused display from the Six Nations champions in the second half.
After 61 minutes, Tuilagi went from provider to try-scorer, smashing through the Romanian line again to touch down next to the posts and take England past the half-century mark.
Croft touched down a few minutes later after a gaping hole opened up down Romania's left flank before Ashton completed his hat-trick following a lolloping run from Haskell.
England: Foden, Ashton, Tuilagi, Tindall, Cueto, Wilkinson, Youngs; Corbisiero, Thompson, Cole, Deacon, Palmer, Croft, Moody, Haskell. Replacements: Mears (for Thompson, 50), Wilson (for Cole 41, Cole for Corbisiero, 58), Shaw (for Deacon, 58), Wood (for Moody, 60), Wigglesworth (for Youngs, 60), Flood (for Wilkinson, 41), Armitage (for Foden, 51).
Romania: Vlaicu, Ciuntu, Cazan, Dumitras, Apostol, Dumbrava, Sirbu; Nere, Zebega, Florea, Popirlan, Petre, Burcea, Ratiu, Tonita. Replacements: Nicolae for Vlaicu (71), Gal for Cazan (42), Calafeteanu for Sirbu (43), Tincu for Zebega (50), Ion for Florea (61), Macovei for Petre (52). Not Used: Ianus.
Referee: Romain Poite (France)