Wales delivered a performance of contrasting halves in their opening Rugby World Cup match as they produced a bonus-point, six-try win over Georgia in Toyota City.
Tries from Jonathan Davies, Justin Tipuric, Josh Adams and Liam Williams secured the bonus point before half-time.
The fluent first 40 minutes was followed by a scrappy second-half performance against a rejuvenated Georgian side.
Replacement scrum-half Tomos Williams and George North added second-half tries.
Australia now await Wales in what will effectively be a potential Pool D decider in Tokyo on 29 September.
This was the oldest Wales starting side at a Rugby World Cup with an average age of 28 years and 331 days.
Captain Alun Wyn Jones celebrated victory as he equalled Gethin Jenkins' record of 129 Wales caps in front of a crowd of 35,545.
Wales were desperate to finally play following the pre-tournament departure of backs coach Rob Howley over an alleged betting breach.
Preparations had already been checked by three warm-up defeats and injuries to Gareth Anscombe and Taulupe Faletau even before the Howley bombshell was revealed.
Wales' early pace
After backs coach Howley was sent home from Japan, he was replaced by former Wales fly-half Stephen Jones who only had two training sessions with the squad before the opening fixture.
Jones knows many of the Wales players, having coached them at Scarlets and there appeared to be little early disruption.
In fact it appeared a more seamless transition with Georgia unable to cope with Wales' pace in the opening period.
Wales took only until the third minute to open the scoring with a well-worked backs move, the nation's fastest ever World Cup try.
Centre Jonathan Davies sliced through the Georgian defence from a slick scrum set-piece move from Gareth Davies' pass.
Dan Biggar inexplicably missed the conversion in front of the posts after he seemed to be struggling to shake off a knock in the warm-up which left him with a gashed chin.
The battered Northampton fly-half experienced a bruising game but recovered in time to add a penalty as Wales benefited from an early strong scrum, a major reason why Wyn Jones was selected at loose-head prop.
More backline chemistry followed between wing Adams and scrum-half Davies, leading to the second try for flanker Tipuric, who produced a clever finish.
Rampant Adams
Biggar this time slotted the conversion from under the posts and turned creator with a delayed inside pass to release Adams.
The wing ran rampant in the opening quarter and scorched over for a deserved try. Normal service resumed as Biggar slotted over the touchline conversion.
Georgia's first break could have resulted in a yellow card for Wales scrum-half Davies after he intercepted a pass from flanker Giorgi Tkhilaishvili, but the ball was adjudged to have gone backwards after being referred to the television match official Rowan Kitt.
Milton Haig's side were inspired and started to secure some scrum pressure, but strong Welsh defence held them out, typified by a thumping Josh Navidi tackle.
Wales secured the bonus point before half-time with a well-worked fourth score with the Scarlets Davies boys, centre Jonathan and scrum-half Gareth, setting up Liam Williams, who finished with an audacious pick-up.
Georgia battled back at the start of the second half with a try for hooker Shalva Mamukashvili from a typical driving line-out. Fly-half Tedo Abzhandadze converted.
Wales responded with a rampaging forward drive of their own which was brought down illegally, earning replacement hooker Jaba Bregvadze a yellow card from referee Luke Pearce.
Georgia ensured their numerical disadvantage did not tell with some thunderous tackling against some one-dimensional attack with Wales failing to scoring any points when they had the extra man.
Wales broke their second-half deadlock when a North chip kick was gathered by replacement scrum-half Tomos Williams before Biggar converted, but Georgia stormed back for their second try through Bregvadze.
Wales had the final word when replacement scrum-half Williams returned the favour to set up North and replacement full-back Leigh Halfpenny converted.
Lock worries
A bruising battle with no long-term injuries would have pleased Gatland especially as Wales still only have two fit-second rows with Jake Ball and captain Jones and back-rower Aaron Shingler covering the position.
Adam Beard only arrived in Japan on Friday after having his appendix removed with Gatland saying he probably would not be fit for the Australia match and post-match revealing Cory Hill could be sent home without playing a game as he struggles to overcome a stress fracture in the leg.
Wales will need all their firepower against the Wallabies.
What the coaches said
Wales coach Warren Gatland: "We needed that.
"I have been watching the games in the last few days and the guys were itching to get out there and I am pleased with the first-half performance.
"I thought we were pretty clinical and probably let things slip a bit in the second-half.
That probably did not help because we were losing some continuity and making some changes with the subs and bringing people off, trying to think about keeping players as fresh as we possibly can with the six day turnaround.
Georgia coach Milton Haig added: "I thought we played pretty well in that second half and we showed our typical Georgian fighting spirit that we're known for, so I'm proud of how they went in that second half."
Man of the Match - Justin Tipuric
Wales: L Williams (Halfpenny, 60); North, J Davies, Parkes, Adams; Biggar (Patchell, 67), G Davies (T Williams, 48); Wyn Jones (Smith, 56), Owens (Dee, 56), Francis (Lewis, 47), Ball (Shingler, 62), Alun Wyn Jones (capt), Wainwright (Moriarty, 51), Tipuric, Navidi.
Replacements: Smith, Dee, Lewis, Shingler, Moriarty, T Williams, Patchell, Halfpenny.
Georgia: Matiashvili; Modebadze, Kacharava, Mchedlidze, Kveseladze; Abzhandadze, Lobzhanidze; Nariashvili (capt; Gogichashvili, 47), Mamukashvili (Saginadze 58), Gigashvili (Chilachava, 47), Nemsadze, Mikautadze (Sutiashvili, 51), Tkhilaishvili (Mamukashvili, 55), M Gorgodze (Giorgadze, 60), B Gorgodze.
Replacements: Bregvadze, Gogichashvili, Chilachava, Sutiashvili, Saginadze, Giorgadze, Aprasidze, Khmaladze.
Officials: Referee, Luke Pearce (England)
Assistant referees: Ben O'Keefe (New Zealand), Mathew Carley (England)
TMO: Rowan Kitt (England)