Spence, ranked fifth in the world and a silver medallist at the season opening World Cup in the USA, crossed the line in the run/shoot 11 seconds ahead of her team-mate after a consistent day which saw her rank third in the fencing, eighth in the swim and third in the final combined discipline.
But there was disappointment for Katy Burke and Freyja Prentice who missed out on progress from their semi-final.
Prentice - the only British women to achieve the Olympic qualifying standard so far - was well outside the top 12 qualifying places in 18th while Burke, in her first World Cup of the season, was marginally better in 14th.
