Stephen Jelley topped a closely bunch lead group in the test session for the Porsche Carrera Cup GB ahead of this weekend's two races at Knockhill.

The session was interrupted by a total of three red flags and the field of Porsches made for a busy time around the 2km traffic as the faster men had to negotiate the traffic of the two Pro-Am classes.

Admitting he lucked into a clear section of track Jelley led the session around the Fife track but only a fraction a second ahead of his Parker with Juta teammate Euan Hankey and the pair of SAS/Redline drivers Michael Meadows and James Sutton, who was only 0.235 seconds down on the top time. The close bunching hopefully a prologue to a tight weekend of racing for the championship.

One of the crucial factors proved to be when drivers elected to take their new tyres during the 45-minute session. Jelley made his switch early in the 45 minute session with Hankey electing to switch later before a final tilt on the best time. However, he dismissed the two laps on new tyres as “scruffy”.

In the Pro-Am classes it was a fine day for home team Celtic Speed. Rory Butcher inflicted a rare Pro-Am defeat on Jonas Gelzinis.

“That was a really tough session and it was hard to get a lap in,” Butcher said. “It's good to be P1, but Jonas will be quick as always.” Gelzinis, however warned he felt there was more improvement to be had.

Butcher's fellow Scot George Brewster led the Pro-Am2 contingent, another man to benefit from fresh tyres during the session.

“We found 1.3s on the new tyres and the car feels fantastic,” he reported. “We've got a completely new set-up on the car and it just feels like a different car.”

Brewster will have to face a class devoid of two of its normal front runners. Redline Racing man Keith Webster spun into the Clark Corner gravel only for Steve Parish to clatter into the stranded Porsche. With both cars significantly damaged both drivers will have to spend the weekend as spectators.