Halifax suffered a third Championship loss of the season, with a late penalty from Toulouse winger Paul Marcon steering the French side to a dour 12-10 win at the Shay.
In a game that was always close on the scoreboard, a controversial penalty from referee Chris Campbell gave Marcon the chance to break a 10-10 deadlock with just four minutes remaining with a super kick from close to the sideline, 40 metres out.
It was a decision that was cruel on the alleged offender Jacob Fairbank, who turned in a full-blooded 80-minute performance.
The home side scored the first try when centre Steve Tyrer pounced on a slide-rule kick from Scott Murrell to score.
Tyrer added the conversion from the sideline for a 6-0 lead.
Toulouse drew level through winger Gregory White, Marcon adding a super conversion.
Fax went ahead again as half-time approached, Tyrer kicking an easy penalty, but a moment of magic from Johnathan Ford set up Bastien Ader on the stroke of half-time as the French side went to the break with a 10-8 lead.
The visitors dominated territory and possession during a one-sided third quarter, but it was the home side who managed to level the scores, largely against the run of play, when Johnston was taken high and Tyrer tied things up with an angled penalty 15 minutes from time.
In the end though, it was Toulouse who held their composure to claim victory.
Halifax: Sharp; Saltonstall, Tyrer, Butler, Woodburn-Hall; Murrell, Johnston; Boyle, Kaye, Cahalane, Tangata, Grix, Fairbank. Substitutes: Morris, Mammone, Ambler, Robinson
Toulouse: Maurel; White, Ader, Planas, Marcon; Ford, Robin; Boyer, Marion, Canet, Mika, Curran, Bentley. Substitutes: Kriouache, Pech, Hepi, Leha
Referee: C Campbell (England).