A gamble on tyres paved the way for Jonny Adam and Andrew Howard to take an comparatively easy victory in the first of two one hour races at Rockingham for the Avon Tyres British GT championship.

An morning shower meant that the GT field conducted their out lap from the pits on a track best described as 'dry-ish' with the dry line still treacherously greasy. Such were the conditions though Howard took the Beechdean Racing Aston Martin out on slick tyres the car was swapped to treaded Avon rubber at the behest of a decision made by Howard and the Barwell Motorsport run team.

That decision was vindicated almost immediately when Duncan Cameron spun the MTECH Ferrari 458 on the warm up lap, dropping to the back of the field with Michael Guasch's United Autosports Audi. The American had been due to start from pole but a brake malfunction left him stranded as he tied to lead away from the dummy grid.

Against this backdrop and from what was orginally fifth David Jones led into turn one in the PreciSpark Mercedes, Howard assuming the lead at Deene despite only having set the eighth best qualifying time.

Jones, like Howard had opted for treaded tyres for the start of the race, and the advantage was enough to have both men eight seconds clear of Michael Lyons' Ferrari in third place after just one lap.

The weather played a huge part in deciding the race, here the Audi of Jay Palmer and John Bintcliffe kicks up the spray

Then the rain came.

All thoughts of trying to struggle for grip and heat on slick tyres was gone, all those who started on dry tyres having to make an extra pitstop to change to the wet tyres. Lyons and Porsche driver David Ashburn pitted from third and fourth respectively and those who started on wet rose to the top of the field.

Behind Howard and Jones were the pair of Ginetta G55s – Ian Stinton fourth for Stark Racing behind Jody Firth's green-and-white Century Motorsport entry. The early race shuffle had vaulted GT4 leader Dan Denis into fifth, John Dhillon sixth in the GT3B class MTECH Ferrari.

Howard continued to pull away, despite the windscreen wipers on the Aston wiping their last just as the rain began to fall. The problem, Howard admitted after the race, caused greater problems passing traffic, the lead yo-yo-ing lap on lap to ten seconds when the mid-race pit window opened on lap 13.

“They [the wipers] stopped about lap five,” Howard told The Checkered Flag. “But I used to ride a bike where rain gets on your visor, you don't have windscreen wipers on your visor and as long as you're careful. The main thing is you don't get right up the back of someone for three laps because you literally could not see the car in front.”

“When we caught up with cars and also cars coming out having changed tyres it made it difficult and that's why the lap time tend to go all over the place. It's just a bit more difficult really.”

After their compulsory stop Jonny Adam, had maintained the lead with Godfrey Jones and Stefan Hodgetts picking up where their co-drivers left off in second and third, but the best of those team that had been forced into an early tyre stop had leapfrogged into fourth and fifth.

Phil Keen – David Ashburn's co-driver in the no.1 Porsche – took fourth from Charles Bateman in the Scuderia Vittoria Ferrari at Deene and began his chase to take the third step on the podium.

Though greatly improved from the start of the season the GT3 spec Ginettas are still woefully underpowered compared to the more established cars in the class. Keen, despite being another man driving without working wipers, was able to lap two or three seconds faster than Hodgetts, eroding the 14 second advantage in just eight laps, catching Hodgetts at the Deene hairpin – the Ginetta driver, previous of the BTCC and the Trofeo Abarth – swinging onto a wide line for the left hander.

Keen explained his view; “I wasn't really going to try and go past him but he braked early and I was up the inside. I couldn't have been any more on the kerb and he just came straight across and banged into me. I thought he stay wide and carry on I wasn't understeering, wasn't sliding I was on top of the kerb and he came across on me. I had nowhere to go.”

The contact spun the Ginetta, Hodgetts able to continue in fourth recovering in gap to Aaron Scott's GT3B car and Bateman. Keen went onto to pick up third place but was unable to make an impression the Jones' Mercedes ahead – the advantage built up in the initial phase of the race too great to bridge.

Adam crossed the line – much to the jubilation of the team on the pitwall – over forty seconds to the good after controlling the race comfortably during his stint.

“It was just finding a rhythm really and I found one quite early on,” said Adam. “Toward the end the visibility got a little bit worse but we had the gap in hand so I just eased off. The car was faultless, superb. It was an eye-opener, the car handled really, really well in these conditions so hopefully more of the same this afternoon.”

After starting on wet tyres Dan Denis and David McDonald won GT4

Behind the podium finishers Hodgetts held on to fourth – the best result for a Ginetta this season, Scott – he and John Dhillon the lone GT3B runners – an astounding fifth in the Ferrari 430, able to stay ahead of first Bateman then Allan Simonsen in more powerful cars.

As is often the case in British GT races Simonsen was the man on a charge in the latter stages of the race.

After taking the car over from co-driver Hector Lester in thirteenth position, more than a lap off the lead, he had climbed into the top ten only two laps after pit window shut.

The MTECH 458 of Matt Griffin, Michael Simpson in the Stark Ginetta, Adam Wilcox in the Predator CCTV Ferrari 430 and finally Bateman would all watch as the Dane went past, only the leader and Matt Bell – recovering well in the pole-sitting Audi able to match his pace.

Simonsen's raw pace – as opposed to merely that of those immediately around him – was demonstrated when his moved himself back onto the lead lap on the penultimate tour of the race.

Bateman, Wilcox and Simpson went to score points behind Simonsen, Matt Bell taking the final point in tenth to extend the championship advantage over Jim and Glynn Geddie, who could only finish twelfth.

Unsurprisingly given their early pace GT4 victory went to Scuderia Vittoria pair Dan Denis and David McDonald – though McDonald had to complete the second half of the race without wipers, their failure an epidemic throughout the race.

Lotus Sport UK took the other two class podium places. Freddy Nordstrom and Leyton Clarke beating Ollie Jackson and Phil Glew, Glew only taking third in class from Josh Wakefield's Ginetta with three minutes remaining of the race.