With both teams going for the title, England flew out of the blocks, with a try inside three minutes and they looked to be running away with it when they led 31-7 midway through the first half.
But France got back to within 10 points by the break, fighting back as they had at this ground two years ago.
That time, their final try came with the clock in the red, denying them a chance to snatch victory, where this time around they had one final play.
An error from the restart proved costly as England hung on to claim a seventh successive crown, but only after they were pushed as hard as they have been in any game since the last World Cup.
In the end, it was Dow’s second try that proved crucial, even with some sensational goal-kicking from Morgane Bourgeois that almost allowed France to snatch it.
England hit the front after just three minutes. With an extended spell of possession, Zoe Harrison played a grubber into space on the right and Dow needed no second invitation collecting the ball and skipping past Bourgeois to get over. Harrison’s conversion drifted wide but England led 5-0.
France responded immediately with a burst through the middle from Marine Ménager leading to Carla Arbez skipping two tackles to get over.
The game continued at a frenetic pace with England retaking the lead immediately. From a powerful rolling maul, they worked their way into the French 22 before spreading the ball wide for Meg Jones to put Emma Sing over. Harrison converted to make it 12-7 to the home side.
Their rolling maul was doing real damage and from another, Lark Atkin-Davies went over for the third English score after just 12 minutes. Harrison could not convert but England led 17-7.
The bonus point was brought up five minutes later, another rolling maul after France had made a hash of a lineout near their own 22, with Sing once more going over after the ball was spread right. Harrison converted and England pulled clear.
France suffered another blow as Assia Khalfaoui was sin-binned for a head-on-head tackle on Maud Muir and England continued to rack up the points with Claudia MacDonald next to get over after Jones’ long pass took out the remaining French defence. Harrison converted to make it 31-7.
Having been in total control, England needed to defend from a dangerous French attack, but after a number of assaults from close in, a strong counter-ruck allowed them to clear the danger.
However, France did secure a second try on the half-hour, Pauline Bourdon-Sansus pouncing after Harrison was unable to take a low pass from Mo Hunt in her own in-goal. Bourgeois converted once again.
The momentum was with the visitors and after a brilliant 50:22, they went over for their third try shortly before half time, Ménager was the scorer this time after England were given a taste of their own medicine from a rolling maul. Bourgeois’ brilliant conversion from out wide made it 31-21 with a minute to go before the break.
They were not far off a fourth as Ménager burst through following a good strike play off first phase, but she knocked on just as she tried to make the offload that might have put Bourgeois in.
Trailing by 10 points at the break, France almost cut the gap further with a stunning break from Joanna Grisez. England’s defence held up however and denied them. They gave themselves some breathing space from their next possession, a brilliant counter-attack from their own half starting with a wide pass from Harrison to Dow to put her away. When the ball came back across, Harrison again found the gap, putting her skipper Zoe Aldcroft over. Harrison converted to make it 38-21.
France were not done yet though, and from a scrum 30 metres out, they moved the ball wide where Kelly Arbey beat two defenders and raced over for a fourth French try. Bourgeois converted once more.
If England were struggling to contain France, they were much more threatening every time they got the ball, with Dow’s second try rewarding extended pressure after another fine wide pass by Harrison.
A fifth French try with 10 minutes to go brought them back to within eight points, Bourgeois scoring from a clever offload by Axelle Berthoumieu. She converted her own score from the touchline.
They should have been back to within a point after another break, but Ménager held onto the ball and put a foot in touch when she had a two-on-one down the right.
The necessary try finally came, Grisez showing her sevens skills to get over down the left, beating a host of England defenders in her wake. Bourgeois converted from the touchline to make it a one-point game with one play to go.
A French error from the restart denied them a final chance to snatch victory as England held on to claim the title in arguably the greatest game in the history of the Guinness Women’s Six Nations.