The RAF has won the Birkett Six Hour Relay Race at Silverstone for the fourth time, after beating off 69 other teams - including the Army.
The 67th edition of one of the most iconic races in Britain's motorsporting calendar saw 70 cars line up on the famous Silverstone circuit.
Among the teams in action were the RAF, three-time winners in the past, and the Army, who were looking to retain their inter-services championship from last year.
The Royal Navy were unable to field their own side this time but are growing and hope to be able to do so in 2018.
The Army's team manager, Major Farard Darver, said:
"Between us and the RAF... this is where it [the rivalry] culminates, to see, ultimately, who are the champions of the Armed Forces."
Also represented was an Armed Forces Challenge team, including guests from the summer-long Armed Forces Race Challenge series, and Team Brit.
The latter outfit, backed by forces charities, consists of disabled drivers, the majority of whom are military veterans who have sustained serious injuries.
Getting things started for the RAF was Sergeant Chris Slator in his Peugeot 306.
Highly experienced in this event, he'd stay out on track for much longer than planned, producing really consistent lap times before handing over to RAF Senior Aircraftman Dan Smith in his Ford Fiesta - the least powerful car in the team.
Lead car for the Army was Warrant Officer Class 1 Matty Taylor's BMW M3, which also gave them a great start to the race. But after losing Chalkie White's Honda with a blown engine in qualifying they had to change their strategy, with the plan now to keep each driver out for an hour at a time.
Taylor handed over to Dan Tedstone but his race was also over far too soon, meaning the team was down to just three cars.
The forces sides were up against seasoned Birkett entrants with names like the 'Dobbers' - who would go on to win the scratch race in their Radicals - the 'Lovable Rogues' and the 'Mini Kievs'.
Also in action were Top Gear presenters Chris Harris, Rory Reid and Matt Le Blanc in a Mercedes, Rolls Royce and Bentley respectively.
They didn't have a lot of luck though - finishing 69th out of a field of 70.
Things were going well at the halfway stage, however for both the RAF - who were in second place - and the Army, who were up to sixth despite losing Chalkie White and Dan Tedstone.
But disaster then struck for Matty Taylor, who'd given the Army such a good start, who had his day ruined after being hit from behind while the safety car was out, leaving the Army with just two cars. Speaking after the incident, WO1 Taylor said:
"I am pleased that a service team's going to do well but I do look back and think if I hadn't broken - and 'if' is always the worst word you can ever use in motorsport - we could be the ones up there fighting for it."
The RAF, in comparison, had a trouble-free race, with their other drivers Darren Howe and Scott Lawson all contributing plenty of laps, in cars of similar performance, giving team manager Darren Berys relatively few headaches.
The Army service team had worked wonders to get Darren Smee's Honda back on the track, changing a clutch, and they were also called into action to work on Ben Gundry's front suspension. Somehow, they kept the Army's remaining cars in the race.
The RAF hit the front at the four-hour mark, with Darren Howe in his VW Golf and the BMWs of Scott Lawson and Warrant Officer Ed McKean piling on the laps.
With an hour and half to go McKean was hitting the track for a third stint, expecting to be out for an hour, but a fuel spill on the track kept the race under safety car rules for half an hour. It played into the RAF's hands. Sgt Slator said:
"It was a long safety car period, which meant... [we] saved a lot of fuel."
It was a nail-biting finish, with the RAF neck-and-neck with the Production GTI Gentlemen.
They would be the only two teams to complete 155 gross laps, but the airmen finished one minute and two seconds ahead to clinch the race.
The Army, for all their issues, ended 11th, only two laps behind their rivals. The Armed Forces Race Challenge team were to come 18th, with Team Brit 58th.
The day, though, belonged to the RAF. WO McKean said:
"It's a great team effort. This event is all about teamwork. It's not just about individuals driving cars fast, because... one individual could [not] do it."
"Everybody in the team played their part - from the people that help put the fuel in... even [to those who] clean the windscreens."
So the day brought a sweet victory for the RAF, who had the dual joy of winning the 67th Birkett and beating old rivals the Army.
You can see the full race results here.