Sioned Harries scores her first try against South Africa under a pile of bodies.
A hat-trick by barnstorming Number 8 Sioned Harries paved the way for Wales Women to win their first World Cup pool game since 1998, when Rachel Taylor's side defeated South Africa 35-3 at Marcoussis.
Replacement prop Jenny Davies was the other try-scorer as Wales romped to a bonus point victory - although they left it late with Harries completing her hat-trick on the stroke of full time.
Centre Robyn Wilkins brought her kicking boots with her as she added the extras for three of the four tries and added two penalties while fly half Elinor Snowsill slotted a smart drop goal in the first half to set Wales on their way.
Both sides went into the match having lost their previous two pool games and knew a third loss would give them the wooden spoon for the group.
Wilkins and Zandile Nojoko traded early penalties before Wilkins and Snowsill edged Wales in front with a penalty and drop kick.
The Welsh pack stood up to the bigger South African pack where prop Mega York proved a particular thorn in the side, both in the set-piece and in the loose. Captain Rachel Taylor led from the front in defence as South Africa showed glimpses of their ability but Wales' defence held firm.
A turnover on the South African line allowed Wales Harries to plunge over for the game's first try and with Wilkins adding the conversion, Wales went into the break 16-3 ahead.
Davies then plunged over from short range as Wales hunted for tries. Harries bagged her second try when she exploded from a scrum to crash over.
Wales hammered away at the South African line and their patience was rewarded in the final play of the game when Harries somehow dived over in the corner with two defenders hounding her.
The Welsh pack were outstanding individually and as a unit with Taylor exceptional once again. Harries was always a threat with the ball in hand while York proved difficult to bring down with her bullocking runs.
The second row of Jenny Hawkins and Shona Powell-Hughes were also immense.
Halfbacks Sian Moore and Snowsill were composed while the back three of Adi Taviner, Laurie Harries and Dyddgu Hywel constantly looked dangerous with ball in hand.
Wales head coach Rhys Edwards paid tribute to his side who he said finally got what they deserved.
"Deep down we've known that performance was in us. We were unlucky in the Six Nations where we were on the end of some disappointing results," he said.
"Once you are in that short of spiral it is difficult to come out. But we've kept banging away at the door and we knew one day we would get the result. It's very pleasing that the girls went out and executed the game plan perfectly against South Africa. It certainly feels like a weight has been lifted off our shoulders."
Wales U20 duo Leon Brown and Lloyd Lewis face a busy couple of weeks ahead. Not only will they have a Junior World Championship to take part in, they are both sitting A Level exams during the competition.
Wales U20 face a tough group in the Junior World Championship with France, England and Japan lying in wait but Attack coach Jason Strange and back rower Tom Phillips are looking forward to the campaign ahead.
Angus O'Brien has quickly settled into the Wales Sevens squad after solid performances in Hong Kong and Japan. With two rounds remaining in Glasgow and Twickenham on the World Series, WRU TV's Graeme Gillespie chats to the rising star.
Wales winger Luke Morgan has established himself as one of the deadliest finishers on the Sevens World Series. WRU TV's Graeme Gillespie catches up with him on the eve of this weekend's round in Glasgow.
All roads lead to Cardiff on Sunday for the SSE SWALEC Finals Day at the Millennium Stadium. Cambrian Welfare tackle Ystradgynlais in the Bowl final, Ystrad Rhondda play Newcastle Emlyn in the Plate final while defending champions Pontypridd face Bridgend in the Cup final.
WRU Chief Executive Roger Lewis, Deputy Minister for Culture, Sport and Tourism Ken Skates and WRU Chairman Gareth Davies earlier this week launched a new competition in conjunction with the WRU unveiling its archive room.
Welsh players and management joined Deputy Minister for Sport Ken Skates at the Pierhead Building, Cardiff Bay earlier this week to reveal the Union's pioneering school-club hub initiative has been so successful the project will now almost double the scale of the original project.
The Scarlets, Newport Gwent Dragons, Cardiff Blues and the Ospreys look ahead to Judgement Day III which sees the Blues take on the Ospreys (2.30) and the Dragons tackle the Scarlets (4.45pm) at the Millennium Stadium tomorrow afternoon.
Ystradgynlais and Ynysddu played out a titanic struggle at Taffs Well in the SSE SWALEC Bowl semi-final. At the end of the game neither team could be separated after a 15-15 stalemate but Ystradgynlais go through on try count.