A chaotic second Avon Tyres British GT Championship of the day at Oulton Park saw two safety car interventions, near collision in the pitlane, a winner from the back of the grid and enough controversy to keep stewards busy and fans talking well after the engines fell silent.

The Safety Car was first called for as soon as it had pulled off the track to unleash the field for the rolling start. The no.44 ABG Motorsport that won the GT4 class in the day's first race failed to make it Old Hall at the start of race two – Marcus Clutton spinning in the tyre barriers on the outside of the first corner, but as the Safety Car gathered up the field to protect the recovery and repair operation there was already controversy brewing.

Suffering a power steering fluid leak – almost certainly a legacy of race one contact – Tim Bridgman had started from the pitlane, making it out just in time to avoid being lapped as the field completed their opening lap. While he beat the leader – Trackspeed teammate Richard Westbrook – he failed to beat the Safety Car and Bridgman was trapped on the very end of the lead lap, leading the snake of cars behind the safety car. Bridgman was released, but in an effort to make up time skipped the full International layout – complete with Shell Oils hairpin – in favour of cutting the track. The result helped the no.2 car speed towards the back of the field, but drew the attention of the race stewards – calling first the team manager, then the driver to race control, though no punishment was dealt out during the race.

Behind the safety car Richard Westbrook led Allan Simonsen in the Rosso Verde Ferrari 430 Scuderia. Matt Griffin had the MTECH 458 in third, ahead of Matt Bell in the United Autosports Audi – the Beechdean Aston Martin an unsurprising non-starter after engine failure after the checkered flag in race one.

Released from behind the Safety Car Westbrook quickly made up for the lost laps in his opening stint – pulling out a four second lead only for the Safety Car to delete any progress – this time called out for a pair of Ginettas – JHR Developments' no.26 G55 and Scuderia Vittoria's no.50 GT4 class G40.

This second tranche behind the safety car gave rise to different strategies. Tim Bridgman – running a canny, if not clever, race for Trackspeed, pitted the no.2 car – still from the back of the field – seconds inside the window. The following lap a bulk of the field came in – Westbrook, Simonsen, Adam Wilcox in the Predator CCTV 430 Scuderia, both CRS Racing representative and Charles Bateman in the Scuderia Vittoria 458 Italia from ninth having started the race at the back of the grid after having his qualifying time deleted after Saturday's session.

The narrow Oulton Park pitlane was packed – CRS Racing had to push back both their cars, nearly being clipped by the Chevron GR8 as the GT Challenge car left after its stop. Having to make their stop under safety car was also the nightmare scenario for the podium finishers from the earlier race, the first teams to have to serve a longer stop under the new performance balancing rules.

The result – for which a stop extended by 15 seconds must be at least partly to blame – was the no.1 resuming the race sixth among the cars that took their pitstops. The time penalty only compounded strategy errors for United Autosports. Leaving Matt Bell out for an additional lap may have given the team a clearer pitlane to work in, but dropped Michael Gausch outside the top ten. Worse still was the mistake in leaving the sister no.24 car out until the Safety Car was withdraw, leaving Jay Palmer outside the top ten when he eventually took over the car from John Bintcliffe.

Presented with third among those who stopped, Michael Lyons quickly passed Gregor Fisken for second, then overhauled Hector Lester for the lead and made good his escape at the head of the field.

“All along we said if we saw a Safety Car and the window's open we'd do we could to jump in,” said Lyons after the race. “The great thing is it that fact it's the time in the pitlane so we were able to get out and go along. I think we came out third or something and just head down charged and disappeared into the distance. We lost the radio that's the only problem and made it a bit difficult, but the pitboard came out pretty quickly and said all the right things. I'm just so happy.”

David Ashburn was the next to pass Fisken, taking third, before David Jones forced Fisken wide out of Old Hall to move the PreciSpark Mercedes up for fourth.

The Jones twins fourth became third when Hector Lester span the Rosso Verde Ferrari backwards into the gravel at Lodge, rejoining down in eleventh. Then the rasping SLS was handed second by the officials, giving the no.1 car was given a one second stop-go penalty after being adjudged to have not spent the necessary 72 seconds in the pitlane.

Meanwhile Michael Gausch was jumping up the order, taking sixth at Old Hall, with just a hint of completing the pass despite yellow flags for the spun no.45 KTM of Athanasios Ladas – though, again, at the time of writing no action had been taken.

Gausch met resistance in Fisken, the Porsche driver defending his third place as the two drivers went side-by-side down the pit straight, Fisken prolonging his stay in the podium spot by forcing the Audi wide on the exit of Old Hall. Gausch, however, completed the pass, to give he and Matt Bell another trip to the Oulton Park podium – the only pairing to grace the GT3 podium in both races. Fisken's race would be complete after running wide and spinning, falling to fifth behind the no.1 car.

Geddies Jim and Glynn gave CRS Racing their best result on an anonymous return to British GT in sixth, one place ahead of teammates Andrew Tate and Alex Mortimer. Hector Lester battled back to ninth and Julien Draper and Freddie Hetherington completed the top ten, taking the first British GT points in a Ginetta G55, the Century Motorsport crew one of the biggest beneficiaries from the strategy shuffle, running as high a fourth before slipping back in the second half of the race.

GT4 was won by Century Motorsports' G50 driven by Jake Rattenbury and Josh Wakefield, but only after a late change to results as on-track winners Freddy Nordstrom and Leyton Clarke were shifted back to second after making the pass of the lead under yellow flags. The second Lotus Evora completed the class podiums.

The Chevron GR8 – comparatively tiny compared to the GT3 cars – shone again, running as high as ninth, before Jordan Witt made a mistake, instead finishing 12th.

UPDATE: Following the end of the race the No.2 Trackspeed Porsche was penalised 1 minute for Bridgman cutting the circuit under the first safety car. The penalty dropped the car to tenth – the final car on the lead lap.