England scored six tries in 18 minutes as they recovered from 6-0 down to comfortably beat Fiji and claim a place in the last eight of the World Cup.
Eloni Vunakece had put Fiji ahead in a brutal first half at the KC Stadium but Ben Westwood levelled before the break.
Sam Burgess scored seconds after the restart as England put in a much-improved attacking performance.
Two scores from Ryan Hall plus tries from Brett Ferres and Rob Burrow sealed victory before Semi Radradra scored.
Steve McNamara's team were playing their final Group A match and will meet either France or Samoa in their quarter-final.
That match will take place in Wigan next Saturday as England look to secure a spot in the last four and, if results go to form, a match against reigning champions New Zealand.
The day had started on a sad note when the players were told that former England international Steve Prescott had died following a long battle against cancer.
Before the match a minute's silence spontaneously changed into a poignant and moving minute's applause, and after the final hooter the England players joined Fiji for their traditional post-match prayer in another touching gesture.
England expected a tough, physical battle and they certainly got one in the opening half, with front rower Ashton Sims setting the tone for Fiji with a series of in-your-face crunching tackles.
Ashton, one of three Sims brothers in the Fiji starting XIII in addition to Ryan and Daryl Millard and Kevin and Wes Naiqama, pulled off a great try-saving tackle when he dislodged the ball from Sam Burgess as the England forward dived over the line.
Both teams tore into each other in front of 25,114 inside the KC Stadium, with Korbin Sims put on report for a dangerous dump-tackle on prop James Graham.
Graham responded with several physical tackles of his own, seizing upon every opportunity to charge into Korbin.
England dominated possession but could not conjure up the decisive play at the end of their sets and they were almost punished when Sam Tomkins failed to clear a kick from Ryan Millard that brother Daryl eventually touched down.
Video referee Shayne Hayne spent a long time analysing the replays before deciding that Tomkins had been taken out off the ball by Tariq Sims as he tried to make amends for his botched clearance.
But Fiji's endeavours were rewarded when the pugnacious Tariq Sims burst through a hole in the England defensive line after collecting a flat pass from Ryan Millard before laying on a simple finish for Vunakece.
That score came just after the half-hour mark and created an atmosphere of mild panic inside the stadium, but England were level at the break after Sinfield's clever dummy created the opening for Westwood, who was placed on report towards the end of the match, to touch down.
And England led for the first time within a minute of the restart when man of the match Sam Burgess charged over, taking several Fiji players with him.
Seconds earlier Burgess had gathered the ball straight from Sinfield's short restart that the Fijians had allowed to bounce.
From that moment England did not look back, as they found the attacking cohesion they lacked in crucial areas during most of the opening 40 minutes.
Minutes after Burgess's try, England had a six-point cushion as Chris Hill and Rangi Chase combined to send Brett Ferres through.
And when the video referee ruled that Hall's left foot had not made contact with the whitewash as he raced down the right touchline, the match was effectively over as a contest.
England moved 30-6 ahead when a move involving Sinfield, Hill and George Burgess was finished by the impressive Burrow, who was making his first appearance of the tournament.
Hall was the next to score as England turned on the style, profiting from the space created by a curved run from Tomkins.
That made it 34-6 after Sinfield missed the conversion, and although England threatened the Fiji line several more times the final score belonged to winger Radradra, who touched down in the corner.
England coach Steve McNamara: "I was worried that the players might be worried at half-time. That was my concern.
"It was an extremely tough Test match. Fiji have got some very good players.
"They completed at nearly 100% in the first half and gave very little away. We were in a real Test match and I was pleased that we were.
"Obviously I would have liked to have been ahead on the scoreboard but I just thought, if the players adjusted one or two things at the start of the second half, that would make a difference.
"We did that for a period of the second half and then fell back a little bit but I'm really pleased."
Fiji coach Rick Stone: "We didn't help ourselves from that kick-off in the second half. Sam Burgess scored and for the next 10 or 15 minutes we didn't see much ball.
"England were real good for 20 minutes and made us pay. They had good shape and challenged us.
"It's a learning curve for us. I was happy with the first bit and the last bit. We competed hard and, when we got a chance, we threw a couple of bullets at England."
England: Tomkins, Briscoe, Watkins, Cudjoe, Hall, Chase, Sinfield, S. Burgess, McIlorum, Graham, Ferres, Westwood, O'Loughlin. Replacements: Burrow, Farrell, Hill, G. Burgess.
Fiji: K. Naiqama, Koroibete, D. Millard, W. Naiqama, Waqavatu, R. Millard, Groom, A. Sims, Storer, Civoniceva, Bukuya, T. Sims, K. Sims. Replacements: Vunakece, Botiki, Roqica, Evans.
Referee: Ben Cummins (Australia)