England have achieved their first objective of the summer but they will ultimately be judged on their two-game series with the All Blacks.
Steve Borthwick’s side overpowered their hosts but also showed some moments of evasion in the face of a committed Japanese defence.
England started slowly, something typified by Cunningham-South’s juggling act from the first kick-off – nerves on his full debut, perhaps.
Japan, led by former England coach Jones in the first game of his second spell in charge, threw the ball at speed as they looked to impose themselves early on.
But England, in a new era of their own, wrestled back momentum after some huge hits by the impressive Cunningham-South and George Martin, while Underhill was ever present at the breakdown.
Their dominance in the forwards allowed Smith to pull the strings in attack and assert his authority in answer to Borthwick’s biggest conundrum of the summer.
Racing 92’s Owen Farrell is out of the picture and George Ford has an Achilles injury which has set up a tussle of the Smiths, Marcus and Fin, at fly-half.
Marcus was handed the jersey in the Japanese capital and the 25-year-old showed glimpses of brilliance as he timed his line to burst on to Mitchell’s pass before stepping past the final defender to glide over.
If that was the running, next came the hands as his double-pump pass forced the red and white shirts to engage him a second longer, allowing Feyi-Waboso space outside to dot down.
Finally, the boot was brought into play as Smith cut back against the traffic to clip the ball to the opposite touchline with little more than a quick glance for Slade to gather and score.
The game was out of sight when he was caught trying to stop a Japanese attack with an early tackle, and he would not return to the field as Fin Smith took the reins following the 10-minute sin-bin period, but this was vintage Marcus Smith as he looks to lay down a marker in the shirt.
England begin their series with the All Blacks in Dunedin on Saturday, 6 July before moving on to Auckland the following weekend.