It surely could not last, and did not. Back came France to sweep past with two tries, one of them of consuming brilliance, in the space of eight minutes. With less than 10 minutes to go, they were back in the lead at 21-16.
But again they idled, and again they allowed Scotland to overtake them when, with a totally unexpected try with only two minutes to go, who should come accelerating down the straight but the rejuvenated Gavin Hastings himself, with 11 points already to his credit, to touch down between the posts to level the game. He then stepped back to convert his try and win the game by two points.
It was Scotland's first victory in Paris since 1969, when games were played in the gloomy concrete jungle of the Stade Colombes, their first ever at the Parc des Princes, and as thrillingly balanced as any they have achieved. They had swanned through, carrying a perfect record from their two opening matches, while France were limping off to the hard shoulder.
And no shoulders are harder to cry on than those of the French supporters, who whistled them derisively off the field.
If you kept the windows shut tight against the biting wind, and just looked out at the sun and patchy blue sky, you could fool yourself that it was already spring in Paris. The French themselves were equally determined to believe that a fortnight after the shock of Twickenham, the worst of the winter was over. Against Scotland, they could begin to enjoy themselves again and rekindle the flame in time for the World Cup. The French have a wonderful capacity for believing that a little trim of the wick will soon bring back the old glory.
The Scots, too, after beating Ireland - though in truth the decision could have gone either way - were joining in the feast of optimism and talking of broadening out their attack, so a very good game was already being talked about by both sides.
But it was undoubtedly the French who set the pace from their own kick- off, the opening follow-up leading to a kick into the deep right by Christophe Deylaud, and then with a path between the half-backs, a diagonal kick from Thierry Lacroix which dropped beautifully for his captain, Philippe Saint-Andr, to carry across on the left for a try. Lacroix failed with the conversion, and was to have a wretched afternoon with his place-kicking, but France were five points up with only two minutes gone.
That was to be their style throughout the first quarter, with Deylaud sending subtly disguised passes to Philippe Sella, and Jan-Luc Sadourny lurking menacingly at the back. All the same, the Scots were beginning to hold them, and although they came close France did not repeat their score, and in the second quarter, Scotland came increasingly into the game. Sensibly, they did not depend on the promised open play, but ran at the French, kicked high among them and kept them on the defensive so that they were now unproductively attacking from inside their own half.
It was Hastings who turned the tide for them with a penalty kick from five yards inside his own half. And then it was he who ran from deep to set up a base from which Gregor Townsend, helped by a lucky deflection, ran through for a try which took the French by surprise. Hastings converted and added another penalty before the half was over.
For almost the length of the second half, Hastings, playing with a growing authority, was unable none the less to add more than a third penalty. Meanwhile, the French took control once more. First they nibbled away at Scotland's eight-point lead with a Lacroix penalty and a Sadourny drop goal. And then came a fine break from which Guy Accoceberry sent Sadourny in to score, and then an even more delicately contrived try in which Saint- Andr fielded a loose kick across field from Townsend, neatly made room for Sadourny to take on the ball, and then came up on the outside to receive the scoring pass. It was a classic piece of improvisation, and should have sealed the game.
But this counted without the Hastings factor. In the 38th minute of the half, he was slipped the ball by Townsend and came sailing through the centre of the field. He is the not the fastest man in open play, but such is his determination that the moment he got the ball the try was on. And so was the least expected victory so far this season.
France: J-L Sadourny (Colomiers); P Bernat-Salles (Pau), P Sella (Agen), T Lacroix (Dax), P Saint-Andr (Montferrand, capt); C Deylaud (Toulouse), G Accoceberry (Bgles); C Califano (Toulon), J-M Gonzales (Bayonne), L Seigne (Brieve), O Brouzet (Grenoble), O Roumat (Dax), A Benazzi (Agen), L Cabannes (Racing Club), P Benetton (Agen).
Scotland: G Hastings (Watsonians, capt); C Joiner (Melrose), G Townsend (Gala), I Jardine (Stirling County), K Logan (Stirling County); C Chalmers (Melrose), B Redpath (Melrose); D Hilton (Bath), K Milne (Heriot's FP), P Wright (Boroughmuir), D Cronin (Bourges), S Campbell (Dundee HSFP), R Wainwright (West Hartlepool), I Morrison (London Scottish), E Peters (Bath).
Referee: D McHugh (Ireland).