King's Lynn sealed a play-off spot with victory over Birmingham on Wednesday, but lost Kozza Smith to injury.
The Stars edged a 50-43 win at the Norfolk Arena to claim the three points needed to solidify their place in the Elite League's top four.
But it came at a cost, as Smith, 23, collided with team-mate Filip Sitera and suffered a dislocated shoulder,
"Heat two was a disaster for us. Filip's possibly broken a finger," boss Rob Lyon told BBC Radio Norfolk.
By the end of the third race the Brummies led 12-6, but the Stars turned it around with totals of 14 from Kenneth Bjerre, 10 from Niels Kristian Iversen and eight from Mads Korneliussen.
Czech rider Sitera, 23, even battled through the pain to pick up a crucial five points for the home side.
"I think it was a little bit tense at the start, possibly the boys were a bit too wound up for it," Lyon added.
"Birmingham are on a bit of a run, they've had a settled side for the last two months and I thought they'd come here and give it a go.
"Maybe we would have preferred it to be a little bit easier."