Defending champions England kicked off their U20 World Championship campaign with a 59-7 victory over Japan in San Michele.
England were unsurprisingly dominant in the first half but Japan fought back with great hunger after half-time, led well by their pack.
England wasted no time getting started with their try-scoring, with winger George Perkins crashing over after just 35 seconds.
Six more tries came before half-time including doubles for Aaron Morris and Stuart Townsend, as England produced some impressive handling and finishing.
England were so comfortably ahead that they made six of their eight substitutions at half-time.
Inevitably perhaps, being 45-0 in the lead, there was a drop in intensity from England at the start of the second half.
Japan in turned began to show what they could do, putting England's defence under sustained pressure with the eventual reward of a penalty try converted by full-back Ryuji Noguchi.
England went down to 14 men with the sin-binning of centre Max Clarke and the second half was tied at 7-7 going into the final ten minutes.
Will Witty scored on the last play to make it nine tries overall for England and a 59-7 win, but Japan should be proud of their efforts.
Tries: Perkins, Walker, Townsend 2, Morris 2, Howe, Skinner, Witty
Con: Jennings 7
Yellow Card: Clarke
Try: Penalty Try
England: 15 Aaron Morris, 14 George Perkins, 13 Nick Tompkins, 12 Max Clark, 11 Tom Howe, 10 Rory Jennings, 9 Stuart Townsend, 8 James Chisholm, 7 Will Owen, 6 Lewis Ludlam, 5 Charlie Ewels, 4 Will Witty, 3 Paul Hill, 2 Jack Walker, 1 Ellis Genge
Replacements: 16 Jack Innard, 17 Sebastian Adeniran-Olule, 18 Ciaran Parker, 19 Sam Skinner, 20 Charlie Beckett, 21 James Mitchell, 22 Lloyd Evans, 23 Piers O’Conor
Japan: 15 Ryuji Noguchi, 14 Seiya Ozaki, 13 Keisei Kasahara, 12 Yusuke Kajimura, 11 Hirofumi Higashikawa, 10 Taisetsu Kanai, 9 Ryuji Yonemura, 8 Tevita Tatafu, 7 Kosuke Urabe, 6 Faulua Mikisi, 5 Mitsuru Furukawa, 4 Hiroto Kato, 3 Tatsuya Kakimoto, 2 Kosuke Horikoshi, 1 Shogo Miura
Replacements: 16 Ryosuke Iwaihara, 17 Ryoma Kuhara, 18 Yuma Fujino, 19 Tomoki Saitam, 20 Go Maeda, 21 Daiki Nakajima, 22 Ataata Moeakiola, 23 Yuta Yamada