IRB Audio: Man of the Match Leigh Halfpenny on the clash against Japan
If it was another spluttering performance from the home nation, who were reduced to 13 men at one stage in the second half, it was still a case of 'Mission Accomplished' for Sam Warburton and his men.
Five tries ensured they stayed in touch with the unbeaten French and their clash at the Liberty Stadium on Saturday afternoon will be decisive, with the winner likely to meet the reigning IRB Under 19 World Champions New Zealand in the last four.
Having seen the French run in eight tries in their 53-17 demolition of Japan in the opening round of matches in Pool D, Welsh Coach Pat Horgan must have been hoping for something similar.
It had taken his side quite a while to get going in their opening game against Italy, but at least there was a bonus point to savour in the 29-10 win. It took seventy minutes to bag the bonus on Friday, but it came within the first 40 against Japan.
Despite taking a battering in the opening 10 minutes, when a great tackle by Nathan Rees prevented the visitors from taking what would have been a deserved lead, the first-half ended with a Welsh flourish as three tries flowed in the space of 11 minutes.
Invesco Perpetual Man of the Match Leigh Halfpenny made the running for the opening score of the night and Dragons fullback Jason Tovey finished off his good work by picking up five metres out and driving over.
The tough Japanese pack, led by New Zealand import Michael Leitch, made life difficult throughout the night for Wales and the middle part of the first-half remained a stalemate.
It eventually took some creative running by the Welsh midfield to pave the way for Rees to notch the first of his two tries and that was the catalyst for a 10 minute purple patch from the home side.
Skipper Warburton was in for the next try, driving deep into the Japanese 22 to help create an overlap for Luke Ford to score. The bonus try came on the stroke of half-time when Halfpenny skipped out of a tackle and raced 15 metres to score.
Halfpenny also managed to convert all three tries in those final 11 minutes of the half and Wales were sitting pretty comfortably. But the best had come and the rest was pretty mediocre.
The Japanese dominated the second half, Wales paid for their frustration in the shape of yellow cards for Warburton and Sam Hobbs and the visitors outscored their hosts by two tries to one in the final 40 minutes.
Aisea Havea drove over from close range for the first score and then replacement Masatake Mikami grabbed a second when Wales were reduced to 13 men.
There was at least a silver lining for Wales in the shape of Rees's second try six minutes from time after Yasutaka Sasakura had dropped a ball in his own 22 to surrender a gift wrapped score.
Having made 10 changes from the opening game, Horgan has now given everyone in the squad some game time ahead of the crunch assignment with the French. All he has to do now is pick the best of them to reach the semi-finals.
Tries: N Rees (2), J Tovey, L Ford, L Halfpenny
Cons: L Halfpenny (4)
Tries: A Havea, Y Mikami
Wales: Jason Tovey (Dragons); Leigh Halfpenny (Blues), Luke Ford (Blues), Rhys Williams (Scarlets), Nathan Rees (Blues); Dan Biggar (Ospreys), Gareth Williams (Ospreys); Sam Hobbs (Blues), Ryan Prosser (Bristol), Scott Andrews (Blues), Ashley Sweet (Dragons), Jevon Groves (Blues), Lloyd Phillips (Scarlets), Justin Tipuric (Ospreys), Sam Warburton (Capt, Blues)
Replacements: Rhys Lawrence (Ospreys) for Prosser 80; Ryan Bevington (Ospreys) for Phillips 72-76, Hobbs 76; Patrick Palmer (Blues) for Andrews 53; Josh Turnbull (Scarlets) for Warburton 65; Jonathan Davies (Scarlets) for Ford 73; Gareth Owen (Ospreys) for Biggar 73