England withstood a dramatic late fightback from a passionate Tonga to reach their first World Cup final for 22 years.
Prolific winger Jermaine McGillvary scored for the 10th game in a row to put his side on their way to a 20-0 lead but England were hanging on grimly by the end after the Pacific Islanders, roared on by a fervent following of more than 25,000 fans, scored three converted tries in the last seven minutes.
Tonga might have snatched it in the dying seconds when prop Andrew Fifita went on a charge for the line only to lose the ball in the tackle and England clung on for a pulsating 20-18 victory.
It may get tougher for England on the pitch when they face holders Australia in Brisbane next Saturday but at least they will not have to contend with a cauldron-like atmosphere generated by the Tongan supporters, who included King George Tupou VI and turned Mount Smart Stadium into a sea of red.
England held their nerve and also rode their luck to clinch a first final appearance since Denis Betts led them out against Australia at Wembley in 1995.
Tries from McGillvary, Gareth Widdop and John Bateman looked to have made it a routine victory but in the end England were grateful for the precision kicking of Widdop, who added all three conversions and kicked a crucial penalty that proved the difference.
The in-form McGillvary showed his danger early on by collecting Luke Gale's kick to the corner and, although his final pass was intercepted by Michael Jennings, it gave England the early momentum.
A classic break from Widdop, courtesy of an offload from the impressive James Graham then set up the position for McGillvary to race in for the game's opening try, with Brown and Widdop providing the telling passes straight from a scrum.
It was McGillvary's seventh try of the tournament, took his tally for his country to 12 in just 11 appearances and enhanced his burgeoning reputation as a world-class player.
Widdop's conversion went in off an upright and England's luck was also in moments later when Tonga captain Sika Manu thought he had finished off a glorious move from deep inside his own half only for referee Matt Cecchin to rule Jennings had made the final pass from off the ground.
Cecchin also thought Widdop had been tackled when he planted the ball over the line in a second effort after taking Elliott Whitehead's pass 10 metres out but video referee Ben Thaler disagreed and awarded England their second try after 15 minutes.
Widdop's second goal made it 12-0 but England lived dangerously up to half-time, with Tonga's dangerous offloading game causing them all sorts of problems and they were indebted to Widdop's last-ditch tackle on winger Daniel Tupou to keep their advantage intact..
England knew it was their day when Tonga bombed a glorious chance three minutes into the second half, Tupou dropping Will Hopoate's pass with the line at his mercy, and Widdop took the opportunity to put his side three scores in front when he kicked a 50th-minute penalty.
Widdop then supplied the final pass for Bateman to score England's third try after 66 minutes which looked to have put the seal on an impressive victory.
But the few hundred England fans were left biting their nails after Tevita Pangai's 74th-minute try sparked the late comeback, which continued when hooker Siliva Havili skipped over from dummy half and skipper Jason Taumalolo carved out a try for Tui Lolohea, who added all three conversions.