Round two of 2014's Women's World Cup saw Ireland shock New Zealand, who lost a first RWC game since 1991 as they went down 17-14 on Tuesday.
Tries from Heather O'Brien and Alison Miller plus two conversions and a penalty from Niamh Briggs helped see off the Black Ferns in Marcoussis.
Victory puts the Irish atop the pool, with full-back Selica Winiata New Zealand's sole try-scorer.
USA got the day off to an impressive start as they dominated Kazakhstan 47-7, bouncing back from their opening round defeat to Ireland last Friday.
England were next up and they made it two from two with a comfortable 45-5 victory against Spain.
They will face Canada, who beat Samoa 42-7, in Saturday's pool finale to decide top spot.
Wales meanwhile fell to their second defeat of the tournament, losing to Australia, which means they are now unable to qualify for the main knockout stage for World Cup glory.
In the final game of the day, France were too good for South Africa as they scored nine tries to run out 55-3 winners, putting down a significant marker on home soil in Marcoussis.
They will face Australia on Saturday in the Pool C decider but on this form France are going to be a serious threat to New Zealand's title, with number eight Safi N'Diaye impressing.
Round Two - Results
USA 47-7 Kazakhstan
Australia 25-3 Wales
England 45-5 Spain
Canada 42-7 Samoa
New Zealand 14-17 Ireland
France 55-3 South Africa
Pool A: England 10, Canada 10, Spain 0, Samoa 0
Pool B: Ireland 8, New Zealand 6, USA 6, Kazakhstan 0
Pool C: France 10, Australia 8, Wales 0, South Africa 0