Prentice was 15th at last year's World Championships in Crystal Palace
British modern pentathletes Freyja Prentice and Katy Burke recorded career-best results by finishing fifth and sixth at the Cairo World Cup.
The youngsters' performance is a boost for them ahead of next month's World Cup leg in Medway Park, Kent.
They outshone their more experienced team-mates Katy Livingston and Mhairi Spence, who were 26th and 29th.
Prentice's result means she has kept up her record of securing top-10 finishes in each of her World Cup appearances.
The 19-year-old, who has only recently returned to training following injury, was 10th on her World Cup debut in Mexico a year ago and ninth in Rome in May last year.
The British quartet made a strong start to the competition with all four placed in the top 10 after the fencing and swimming.
Burke, 20, strengthened her position further when she was one of only six athletes to score a perfect 1,200 in the riding arena to go into the final run/shoot in the lead, six seconds ahead of Egypt's Aya Medany.
Prentice was sixth in the riding but both Livingston and Spence suffered disappointing horse draws and slipped down the field.
But Burke was only 22nd-fastest in the run/shoot to finish sixth while Prentice was sixth-quickest to finish one place above her.
Jan Bartu, Pentathlon GB performance director, praised the young pair's achievements.
"It was a really good day for the younger members of the team. Katy Burke and Freyja both handled the final like pros," Bartu said.
"We have a second generation of athletes coming through now and that's really encouraging. It's fantastic."