Ricky Stevens and Ryan Charlwood had their hopes of a triple victory at Knockhill dashed by injury.
The 2015 British F1 Sidecar champions were aiming for a stellar show in the third round of the 2016 Hyundai Heavy Industries British Sidecar Championship in Scotland last weekend.
With their main rivals absent because of a fixture clash with the World Championship, the stakes were high for Portsmouth driver Stevens and his Dover-based passenger.
However, their plans were scuppered when Charlwood dislocated his shoulder during the first practice on Friday.
Having fallen off during the opening session, he was unable to take any further part in the weekend – which featured three key races.
Charlwood said: ‘I tried to cling on to the outfit with the G-force fighting against me and that is how I dislocated my shoulder.
‘I realised almost immediately something was wrong and it was a serious injury.
‘I’m really disappointed because Knockhill is my favourite circuit and this was going to be a pivotal weekend for us.
‘I was really looking forward to it.’
With Andy Peach unable to race because of illness, his passenger Charlie Richardson stepped in to partner Stevens.
And despite a very short practice session, the duo managed to secure third spot in the qualifiers.
An clash with another outfit at the start of the first race on Saturday led to a spin and saw the pair finish the first lap in last place.
They managed to claw back some time and finished eighth.
They then notched third spot in the second race.
On Sunday, the pair looked set to win as they held the lead for four laps. But a spin on lap eight dropped them back to third.
Stevens said: ‘We had hoped for a triple victory this weekend, so I’m somewhat disappointed.
‘Losing Ryan was obviously a game-changer. Part of our success is we are so well matched.
‘But Charlie is an experienced passenger and we are so grateful to Andy Peach and their sponsors for letting us have him.
‘I’ve not done as well as I’d hoped but I have still come away leading the championship and that is cause for a celebration.’
The next round is at Snetterton on July 8-10.