King's Lynn Stars battled to victory over Poole Pirates, but hold a narrow 48-45 lead for the second leg of the Elite League play-off semi-final.
The Stars started well, with Olly Allen and Sam Masters impressing.
Poole had to wait until heat seven for their first race advantage, Darcy Ward and Tomas Jonasson securing a 4-2.
But the league leaders kept the pressure on the Stars and finished strongly with a 5-1 from Australian pair Ward and Chris Holder.
"To let it go like that was disappointing," said Stars boss Rob Lyon.
"We've done all the hard work and it's a shame, because I honestly felt after heat 10 we could pull a decent lead.
"You can't take it away from the Aussie boys, they were a class above."
Poole will host the second leg at Wimborne Road on Monday, 26 September.
King's Lynn Stars 48: Kenneth Bjerre 9, Lasse Bjerre 7, Olly Allen 8, Mads Korneliussen 6, Niels-Kristian Iversen 7, Filip Sitera 2, Sam Masters 9
Poole Pirates 45: Chris Holder 14, Kevin Doolan (guest) 1, Davey Watt (rider replacement), Thomas H Jonasson 3, Darcy Ward 17, Kevin Wolbert 10, Morten Risager (g)