The Ireland Women seized the initiative in the second half at foggy Ashbourne as they edged out France 15-10 in a thrilling top of the table clash.
Ireland are now just 80 minutes away from lifting the Women's RBS 6 Nations trophy with Italy the last team standing between them and an incredible Grand Slam success.
Philip Doyle's side could actually be crowned champions tomorrow if the third-placed Italians, who lie on four points, fail to beat England in Esher.
The girls in green have a clear lead at the top of the table, boasting eight points after completing their first ever Triple Crown and beating the French who are now out of the title race in second (four points).
It was another super-charged performance from Ireland at their County Meath base, securing only their second ever win over France – their previous one was at the same venue in 2009 (7-5).
With President of Ireland Michael D Higgins among the crowd of over 3,000, Ashbourne RFC was treated to another terrific advertisement for the women's game as the Championship's two leading sides went toe to toe.
Ireland had to do it the hard way, defending furiously as the wind-backed French attacked with vigour and Sandrine Agricole nudged them ahead in the seventh minute from an excellent penalty on the left.
The heavier French pack tried to set the tone, but Ireland defended magnificently and the visitors were rocked when a fast-packed 16th minute attack sparked the game's opening try.
Clinical attacking had been a hallmark of Ireland's play in this year's Six Nations and Alison Miller, the tournament's top try scorer with five, led a telling surge down her flank.
Lynne Cantwell, the creative hub of the home back-line, thrived on a quick recycle and linked with number 8 Joy Neville who, in turn, brilliantly released Niamh Briggs for a memorable score.
The full-back was unable to convert her own try and France swept into a 10-5 lead for the interval, with Agricole impressively converting a try out wide from hooker Gaëlle Mignot following a strong maul.
Cantwell led the hunt for a late response but a pass to her from Ashleigh Baxter was ruled forward with the French defence under considerable pressure.
Given the strong wind and the power of the French forwards, Ireland had done well to keep the margin to five points.
Claire Molloy and Siobhan Fleming, combining with Neville in the back row, deserve credit for a high tackle count as they kept the likes of Safi N'Diaye, a potent weapon in France's win over England, at bay.
Turning around with the wind behind them, Fiona Coghlan and her team-mates enjoyed a better share of possession in the third quarter and they certainly made it count with Molloy hurtling through on an initial break.
Five minutes in, a well-executed maul drive saw the pack crash over the French line with prop Ailis Egan grounding the ball for a galvanising try, with the home supporters roaring their approval.
Briggs managed to add the extras as the lead changed hands again, and France had to show discipline in defence as the Irish battered forward in search of more tries.
France hung in there as the crowd raised the noise level in support of Ireland. Les Bleues missed a drop goal through replacement Aurélie Bailon as the tension increased.
it was left to Briggs to notch the match-winning score in injury-time, firing over a late penalty after she had struck the post with a similar effort just minutes earlier.
Ireland showed great collective composure and character to grind out a tight result, especially given the high stakes involved. The green juggernaut rolls on to Italy for St. Patrick's weekend, the final leg of a possible Grand Slam.
Referee: Nicky Inwood (New Zealand)