Needing to secure a top 12 place in their respective semi-finals, Spence crossed the line in a comfortable fourth while Olympic silver medallist Heather Fell was just a few places back in eighth.
Samantha Murray, who has been enjoying a breakthrough season, advanced in ninth while Freyja Prentice was an equally comfortable fifth in her semi.
It means all four will get the opportunity to battle it out for individual medals on Saturday – and the chance to achieve the London 2012 Olympic qualifying standard. Prentice is the only British woman pentathlete to have achieved that standard to date but still isn't guaranteed a place on Team GB.
Meanwhile, the biggest surprise of qualifying saw Ukraine’s reigning world champion and Olympic bronze medallist Victoria Tereshuk miss out on the final, finishing a distant 16th in her semi-final.
Jan Bartu, Pentathlon GB performance director, said: “They all qualified for the final and that’s great news. It was a tough day, but they all deserve their places in the final.
“They all looked good today, although they have room for improvement in certain disciplines and they will all start from zero again in the final on Saturday.”