The cohesion showed by the visitors in their first outing was more than a match for their opponents.
Hayle had made several strong summer signings from neighbouring Redruth and St Ives and were confident they could turn around the double achieved last season by their opponents.
St Austell started strongly and kept the home side under pressure with much of the play around their own 22.
Hayle's large pack though started to find their feet and indiscipline around the scrum cost the Saints a penalty in the 34th minute which was converted easily by Hayle fly-half Steve Evans.
This sparked the Saints into action and a blistering run of play from the restart had Alex Welland screaming through the Hayle 22 to score out wide.
With the conversion missed and just a couple of minutes to go to half time indiscipline again gave Hayle a break through and Richard Humphries burst through to regain the lead for Hayle and the conversion by Evans wrapped up the half at 10-5 to the home side.
Again the Saints started the second half strongly and pressured the Hayle line, but it was the home team who had the penalty chances, though luckily for the Saints these went wide. And it was Andy Ashwin who stepped up to strike a perfect kick and reduce the deficit to two points.
St Austell's centre combination of James Earp and Murphy, with great support from Ian Venner, started to stretch the Hayle defence and after a perfect line out in the Hayle half and quick hands it was Earp who punished them by scoring under the posts for Ashwin to convert.
With the score now at 15-10 in St Austell's favour, the pressure was mounting on Hayle and with the ever present Paul Winterbottom's tackling this proved to be a catalyst for a slight difference in opinions between the teams.
Skipper Adam Kellow was replaced by Darren Thompson with a blood injury and Hayle then reduced the lead to two points with a penalty.
Again Ashwin returned the favour and the Saints held on for the win in a torrid last five minutes.
Man of the Match: Alex Welland.
Scorers. Hayle: try, Humphries; pens, Evans (2); conversion, Evans.
St Austell: tries, Alex Welland, James Earp; pens, Andy Ashwin (2); conversion, Andy Ashwin.