Sutton moved to the top of the order early on in the session and then gradually kept whittling his time down to record an eventual best of one minute 39.928 seconds in his BMR Restart-backed Team Pyro car.
Maximum Motorsport’s Ant Whorton-Eales got nearest to him with a time of 1m40.004s – just 0.076s behind. Championship leader, Pyro’s Ash Hand, was third (1m40.204s) and title outsider, WDE Motorsport’s Paul Rivett, fourth (1m40.456s). WDE’s Dan Holland, fifth on 1m40.999s, was the only other driver to break the 1m41s barrier.
Sutton, who is feeling unwell, said: "The track was still damp in places on the GP section under the trees when we first ventured out but that suits my style so I was on the pace quickly. I think that made a few others sit up and take notice. I'm very happy with my performance and my best time near the end was set when I had to overtake two slower cars. It will be interesting to see what gains can be made when we put new tyres on in this afternoon's session."
Whorton-Eales said: "I'd imagine new tyres will see us down in the low 1m39s. I'm please with how that went – we are in the ballpark straight away."
And added Hand: "I'm very happy with that – we're not showing our true pace yet and I was also driving within track limits which I'm not sure was the case with some and that is a bit silly if they weren't."
Rivett commented: "A very straight forward session, although I did see Sam Watkins have a hairy moment exiting Hawthorns and then came through Clearways to find George Jackson going slow in the middle of the track! I only used one old set of tyres during the session but, put some new boots on, and I'm sure we can go with the other three later today."
Pyro’s Josh Price was sixth and closely followed by Paul Streather – an excellent seventh in his first official UK Clio Cup session with the returning Finesse Motorsport squad – and JamSport Racing pair Tom Grundy and Luke Kidsley. Cooksport’s Jon Maybin completed the top ten ahead of Ben Palmer, who also showed strongly ahead of his UK Clio Cup debut with 20Ten Racing with the 11th fastest time.
The 20 cars entered for this weekend’s title-deciding rounds all took part in the session and will be back out on track again later this afternoon at 3.15pm.
CLICK HERE for the full test session times.